Release v2.1.2

* Now compiling using truffle 5.

* Migrated some test files, missing BN scientific notation usage.

* Now using BN time values.

* Migrate ERC20 tests.

* Migrate all ERC20 tests.

* Migrate utils, payment and ownership tests.

* All tests save ERC721 migrated.

* Migrated ERC721 tests.

* Fix lint errors.

* Delete old test helpers.

* Fix remaining crowdsale tests.

* Fix signature bouncer tests.

* Update how constants is used.

* Compile script pre-removes the build dir.

* Fix SafeMath tests.

* Revert "Compile script pre-removes the build dir."

This reverts commit 247e745113.

* Fix linter errors.

* Upgrade openzeppelin-test-helpers dependency.

* Update openzeppelin-test-helpers dependency.

* Define math constants globally.

* Remove unnecessary ether unit.

* Roll back reduced ether amounts in tests.

* Remove unnecessary toNumber conversions.

* Delete compile script.

* Fixed failing test.

.env.example

@@ -1,5 +0,0 @@
-# configure your infura api key (not technically required)
-INFURA_API_KEY=
-
-# change the mnemonic that your hd wallet is seeded with
-MNEMONIC=

.eslintrc

@@ -1,22 +1,23 @@
 {
   "extends" : [
     "standard",
-    "plugin:promise/recommended"
+    "plugin:promise/recommended",
   ],
   "plugins": [
-    "promise"
+    "mocha-no-only",
+    "promise",
   ],
   "env": {
     "browser" : true,
     "node"    : true,
     "mocha"   : true,
-    "jest"    : true
+    "jest"    : true,
   },
   "globals" : {
     "artifacts": false,
     "contract": false,
     "assert": false,
-    "web3": false
+    "web3": false,
   },
   "rules": {
 
@@ -49,6 +50,8 @@
     "semi": ["error", "always"],
     "space-before-function-paren": ["error", "always"],
 
+    "mocha-no-only/mocha-no-only": ["error"],
+
     "promise/always-return": "off",
     "promise/avoid-new": "off",
   }

.github/ISSUE_TEMPLATE.md

@@ -1,34 +0,0 @@
-## 🎉 Description
-
-<!-- Briefly describe the issue you are experiencing (or the feature you want to see added to OpenZeppelin). Tell us what you were trying to do and what happened instead. **Remember, this is _not_ a place to ask for help debugging code; for that, we welcome you in the [OpenZeppelin Slack Channel](https://slack.openzeppelin.org/).** -->
-
-- [ ] 🐛 This is a bug report.
-- [ ] 📈 This is a feature request.
-
-<!-- Please check one of the above by placing an x in the box. -->
-
-## 💻 Environment
-
-Next, we need to know what your environment looks like.
-
-- Which version of OpenZeppelin are you using?
-- What network are you deploying to? Ganache? Ropsten?
-- How are you deploying your OpenZeppelin-backed contracts? truffle? Remix? Let us know!
-
-## 📝 Details
-
-Describe the problem you have been experiencing in more detail. Include as much information as you think is relevant. Keep in mind that transactions can fail for many reasons; context is key here.
-
-## 🔢 Code To Reproduce Issue [ Good To Have ]
-
-Please remember that with sample code it's easier to reproduce the bug and it's much faster to fix it.
-
-```
-insert short code snippets here
-```
-
-<!-- If your code is larger, consider linking us to a repo illustrating your issue. -->
-
-## 👍 Other Information
-
-<!-- List any other information that is relevant to your issue. Error logs, related issues, suggestions on how to fix, Stack Overflow links, forum links, etc. -->

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,21 @@
+---
+name: Bug report
+about: Report a bug in OpenZeppelin
+
+---
+
+<!-- Briefly describe the issue you're experiencing. Tell us what you were trying to do and what happened instead. -->
+
+<!-- Remember, this is not a place to ask for help debugging code. For that, we welcome you in the OpenZeppelin Slack channel: https://slack.openzeppelin.org/. -->
+
+**💻 Environment**
+
+<!-- Tell us what version of OpenZeppelin you're using, and how you're using it: Truffle, Remix, etc. -->
+
+**📝 Details**
+
+<!-- Describe the problem you have been experiencing in more detail. Include as much information as you think is relevant. Keep in mind that transactions can fail for many reasons; context is key here. -->
+
+**🔢 Code to reproduce bug**
+
+<!-- We will be able to better help if you provide a minimal example that triggers the bug. -->

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,14 @@
+---
+name: Feature request
+about: Suggest an idea for OpenZeppelin
+
+---
+
+**🧐 Motivation**
+<!-- Is your feature request related to a specific problem? Is it just a crazy idea? Tell us about it! -->
+
+**📝 Details**
+<!-- Please describe your feature request in detail. -->
+
+<!-- Make sure that you have reviewed the OpenZeppelin Contributor Guidelines. -->
+<!-- https://github.com/OpenZeppelin/openzeppelin-solidity/blob/master/CONTRIBUTING.md -->

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,17 +1,21 @@
 <!-- 0. 🎉 Thank you for submitting a PR! -->
 
-<!-- 1. **Does this close any open issues?** If so, list them here. If not, remove the `Fixes #` line. -->
+<!-- 1. Does this close any open issues? Please list them below. -->
+
+<!-- Keep in mind that new features have a better chance of being merged fast if
+they were first discussed and designed with the maintainers. If there is no
+corresponding issue, please consider opening one for discussion first! -->
 
 Fixes #
 
-# 🚀 Description
-
-<!-- 2. Describe the changes introduced in this pull request -->
+<!-- 2. Describe the changes introduced in this pull request. -->
 <!--    Include any context necessary for understanding the PR's purpose. -->
 
-<!-- 3. Before submitting, please review the following checklist: -->
-
-- [ ] 📘 I've reviewed the [OpenZeppelin Contributor Guidelines](../blob/master/CONTRIBUTING.md)
-- [ ] ✅ I've added tests where applicable to test my new functionality.
-- [ ] 📖 I've made sure that my contracts are well-documented.
-- [ ] 🎨 I've run the JS/Solidity linters and fixed any issues (`npm run lint:fix`).
+<!-- 3. Before submitting, please make sure that you have:
+  - reviewed the OpenZeppelin Contributor Guidelines
+    (https://github.com/OpenZeppelin/openzeppelin-solidity/blob/master/CONTRIBUTING.md),
+  - added tests where applicable to test new functionality,
+  - made sure that your contracts are well-documented,
+  - run the JS/Solidity linters and fixed any issues (`npm run lint:fix`), and
+  - updated the changelog, if applicable.
+-->

.solhint.json

@@ -0,0 +1,11 @@
+{
+  "extends": "default",
+  "rules": {
+    "indent": ["error", 4],
+
+    "bracket-align": false,
+    "compiler-fixed": false,
+    "no-simple-event-func-name": false,
+    "two-lines-top-level-separator": false
+  }
+}

.soliumignore

@@ -1 +0,0 @@
-node_modules

.soliumrc.json

@@ -1,21 +0,0 @@
-{
-  "extends": "solium:all",
-  "plugins": ["security"],
-  "rules": {
-    "blank-lines": "off",
-    "error-reason": "off",
-    "indentation": ["error", 2],
-    "lbrace": "off",
-    "linebreak-style": ["error", "unix"],
-    "max-len": ["error", 79],
-    "no-constant": ["error"],
-    "no-empty-blocks": "off",
-    "quotes": ["error", "double"],
-    "uppercase": "off",
-    "visibility-first": "error",
-
-    "security/enforce-explicit-visibility": ["error"],
-    "security/no-block-members": ["warning"],
-    "security/no-inline-assembly": ["warning"]
-  }
-}

.travis.yml

@@ -15,29 +15,27 @@ jobs:
   # --elopio - 20180531
   fast_finish: true
   allow_failures:
-    - env: SOLIDITY_COVERAGE=true
     - env: SOLC_NIGHTLY=true
   include:
-    # Run the unit test suite three times in parallel.
-    # The first one gets results faster and is the only one required to pass.
-    # The second one generates the coverage report.
-    # The third one is to keep us informed about possible issues with the
-    # upcoming solidity release.
     - stage: tests
-      name: "unit tests"
+      name: "Linter"
+      script: npm run lint
+
+    - stage: tests
+      name: "Unit tests"
       script: npm run test
+
+# solidity-coverage fails at parsing 0.5.x code
+#    - stage: tests
+#      name: "Unit tests with coverage report"
+#      script: npm run test
+#      env: SOLIDITY_COVERAGE=true
+
     - stage: tests
-      name: "unit tests with coverage"
-      script: npm run test
-      env: SOLIDITY_COVERAGE=true
-    - stage: tests
-      name: "unit tests with solc nightly"
+      name: "Unit tests using solc nightly"
       script: npm run test
       env: SOLC_NIGHTLY=true
-    # solidity and javascript style tests.
-    - stage: tests
-      name: "static tests"
-      script: npm run lint
+
     - stage: update docs
       if: tag =~ ^v[0-9]+\.[0-9]+\.[0-9]+$
       addons:

CHANGELOG.md

@@ -0,0 +1,37 @@
+# Changelog
+
+## 2.2.0 (unreleased)
+
+## 2.1.2 (2019-17-01)
+ * Removed most of the test suite from the npm package, except `PublicRole.behavior.js`, which may be useful to users testing their own `Roles`.
+
+## 2.1.1 (2019-04-01)
+ * Version bump to avoid conflict in the npm registry.
+
+## 2.1.0 (2019-04-01)
+
+### New features:
+ * Now targeting the 0.5.x line of Solidity compilers. For 0.4.24 support, use version 2.0 of OpenZeppelin.
+ * `WhitelistCrowdsale`: a crowdsale where only whitelisted accounts (`WhitelistedRole`) can purchase tokens. Adding or removing accounts from the whitelist is done by whitelist admins (`WhitelistAdminRole`). Similar to the pre-2.0 `WhitelistedCrowdsale`. ([#1525](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1525), [#1589](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1589))
+ * `RefundablePostDeliveryCrowdsale`: replacement for `RefundableCrowdsale` (deprecated, see below) where tokens are only granted once the crowdsale ends (if it meets its goal). ([#1543](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1543))
+ * `PausableCrowdsale`: allows for pausers (`PauserRole`) to pause token purchases. Other crowdsale operations (e.g. withdrawals and refunds, if applicable) are not affected. ([#832](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/832))
+ * `ERC20`: `transferFrom` and `_burnFrom ` now emit `Approval` events, to represent the token's state comprehensively through events. ([#1524](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1524))
+ * `ERC721`: added `_burn(uint256 tokenId)`, replacing the similar deprecated function (see below). ([#1550](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1550))
+ * `ERC721`: added `_tokensOfOwner(address owner)`, allowing to internally retrieve the array of an account's owned tokens. ([#1522](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1522))
+ * Crowdsales: all constructors are now `public`, meaning it is not necessary to extend these contracts in order to deploy them. The exception is `FinalizableCrowdsale`, since it is meaningless unless extended. ([#1564](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1564))
+ * `SignedSafeMath`: added overflow-safe operations for signed integers (`int256`). ([#1559](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1559), [#1588](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1588))
+
+### Improvements:
+ * The compiler version required by `Array` was behind the rest of the libray so it was updated to `v0.4.24`. ([#1553](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1553))
+ * Now conforming to a 4-space indentation code style. ([1508](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1508))
+ * `ERC20`: more gas efficient due to removed redundant `require`s. ([#1409](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1409))
+ * `ERC721`: fixed a bug that prevented internal data structures from being properly cleaned, missing potential gas refunds. ([#1539](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1539) and [#1549](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1549))
+ * `ERC721`: general gas savings on `transferFrom`, `_mint` and `_burn`, due to redudant `require`s and `SSTORE`s. ([#1549](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1549))
+
+### Bugfixes:
+
+### Breaking changes:
+
+### Deprecations:
+ * `ERC721._burn(address owner, uint256 tokenId)`: due to the `owner` parameter being unnecessary. ([#1550](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1550))
+ * `RefundableCrowdsale`: due to trading abuse potential on crowdsales that miss their goal. ([#1543](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1543))

README.md

@@ -1,8 +1,8 @@
 # <img src="logo.png" alt="OpenZeppelin" width="400px">
 
 [![NPM Package](https://img.shields.io/npm/v/openzeppelin-solidity.svg?style=flat-square)](https://www.npmjs.org/package/openzeppelin-solidity)
-[![Build Status](https://img.shields.io/travis/OpenZeppelin/openzeppelin-solidity.svg?branch=master&style=flat-square)](https://travis-ci.org/OpenZeppelin/openzeppelin-solidity)
-[![Coverage Status](https://img.shields.io/coveralls/github/OpenZeppelin/openzeppelin-solidity/master.svg?style=flat-square)](https://coveralls.io/github/OpenZeppelin/openzeppelin-solidity?branch=master)
+[![Build Status](https://travis-ci.com/OpenZeppelin/openzeppelin-solidity.svg?branch=master)](https://travis-ci.com/OpenZeppelin/openzeppelin-solidity)
+[![Coverage Status](https://coveralls.io/repos/github/OpenZeppelin/openzeppelin-solidity/badge.svg?branch=master)](https://coveralls.io/github/OpenZeppelin/openzeppelin-solidity?branch=master)
 
 **OpenZeppelin is a library for secure smart contract development.** It provides implementations of standards like ERC20 and ERC721 which you can deploy as-is or extend to suit your needs, as well as Solidity components to build custom contracts and more complex decentralized systems.
 

RELEASING.md

@@ -34,7 +34,7 @@ git push upstream vX.Y.Z-rc.R
 
 Draft the release notes in our [GitHub releases](https://github.com/OpenZeppelin/openzeppelin-solidity/releases). Make sure to mark it as a pre-release! Try to be consistent with our previous release notes in the title and format of the text. Release candidates don't need a detailed changelog, but make sure to include a link to GitHub's compare page.
 
-Once the CI run for the new tag is green, publish on npm under the `next` tag.
+Once the CI run for the new tag is green, publish on npm under the `next` tag. You should see the contracts compile automatically.
 
 ```
 npm publish --tag next
@@ -62,7 +62,7 @@ git push upstream vX.Y.Z
 
 Draft the release notes in GitHub releases. Try to be consistent with our previous release notes in the title and format of the text. Make sure to include a detailed changelog.
 
-Once the CI run for the new tag is green, publish on npm.
+Once the CI run for the new tag is green, publish on npm. You should see the contracts compile automatically.
 
 ```
 npm publish

contracts/access/Roles.sol

@@ -1,44 +1,40 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 /**
  * @title Roles
  * @dev Library for managing addresses assigned to a Role.
  */
 library Roles {
-  struct Role {
-    mapping (address => bool) bearer;
-  }
+    struct Role {
+        mapping (address => bool) bearer;
+    }
 
-  /**
-   * @dev give an account access to this role
-   */
-  function add(Role storage role, address account) internal {
-    require(account != address(0));
-    require(!has(role, account));
+    /**
+     * @dev give an account access to this role
+     */
+    function add(Role storage role, address account) internal {
+        require(account != address(0));
+        require(!has(role, account));
 
-    role.bearer[account] = true;
-  }
+        role.bearer[account] = true;
+    }
 
-  /**
-   * @dev remove an account's access to this role
-   */
-  function remove(Role storage role, address account) internal {
-    require(account != address(0));
-    require(has(role, account));
+    /**
+     * @dev remove an account's access to this role
+     */
+    function remove(Role storage role, address account) internal {
+        require(account != address(0));
+        require(has(role, account));
 
-    role.bearer[account] = false;
-  }
+        role.bearer[account] = false;
+    }
 
-  /**
-   * @dev check if an account has this role
-   * @return bool
-   */
-  function has(Role storage role, address account)
-    internal
-    view
-    returns (bool)
-  {
-    require(account != address(0));
-    return role.bearer[account];
-  }
+    /**
+     * @dev check if an account has this role
+     * @return bool
+     */
+    function has(Role storage role, address account) internal view returns (bool) {
+        require(account != address(0));
+        return role.bearer[account];
+    }
 }

contracts/access/roles/CapperRole.sol

@@ -1,43 +1,43 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../Roles.sol";
 
 contract CapperRole {
-  using Roles for Roles.Role;
+    using Roles for Roles.Role;
 
-  event CapperAdded(address indexed account);
-  event CapperRemoved(address indexed account);
+    event CapperAdded(address indexed account);
+    event CapperRemoved(address indexed account);
 
-  Roles.Role private cappers;
+    Roles.Role private _cappers;
 
-  constructor() internal {
-    _addCapper(msg.sender);
-  }
+    constructor () internal {
+        _addCapper(msg.sender);
+    }
 
-  modifier onlyCapper() {
-    require(isCapper(msg.sender));
-    _;
-  }
+    modifier onlyCapper() {
+        require(isCapper(msg.sender));
+        _;
+    }
 
-  function isCapper(address account) public view returns (bool) {
-    return cappers.has(account);
-  }
+    function isCapper(address account) public view returns (bool) {
+        return _cappers.has(account);
+    }
 
-  function addCapper(address account) public onlyCapper {
-    _addCapper(account);
-  }
+    function addCapper(address account) public onlyCapper {
+        _addCapper(account);
+    }
 
-  function renounceCapper() public {
-    _removeCapper(msg.sender);
-  }
+    function renounceCapper() public {
+        _removeCapper(msg.sender);
+    }
 
-  function _addCapper(address account) internal {
-    cappers.add(account);
-    emit CapperAdded(account);
-  }
+    function _addCapper(address account) internal {
+        _cappers.add(account);
+        emit CapperAdded(account);
+    }
 
-  function _removeCapper(address account) internal {
-    cappers.remove(account);
-    emit CapperRemoved(account);
-  }
+    function _removeCapper(address account) internal {
+        _cappers.remove(account);
+        emit CapperRemoved(account);
+    }
 }

contracts/access/roles/MinterRole.sol

@@ -1,43 +1,43 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../Roles.sol";
 
 contract MinterRole {
-  using Roles for Roles.Role;
+    using Roles for Roles.Role;
 
-  event MinterAdded(address indexed account);
-  event MinterRemoved(address indexed account);
+    event MinterAdded(address indexed account);
+    event MinterRemoved(address indexed account);
 
-  Roles.Role private minters;
+    Roles.Role private _minters;
 
-  constructor() internal {
-    _addMinter(msg.sender);
-  }
+    constructor () internal {
+        _addMinter(msg.sender);
+    }
 
-  modifier onlyMinter() {
-    require(isMinter(msg.sender));
-    _;
-  }
+    modifier onlyMinter() {
+        require(isMinter(msg.sender));
+        _;
+    }
 
-  function isMinter(address account) public view returns (bool) {
-    return minters.has(account);
-  }
+    function isMinter(address account) public view returns (bool) {
+        return _minters.has(account);
+    }
 
-  function addMinter(address account) public onlyMinter {
-    _addMinter(account);
-  }
+    function addMinter(address account) public onlyMinter {
+        _addMinter(account);
+    }
 
-  function renounceMinter() public {
-    _removeMinter(msg.sender);
-  }
+    function renounceMinter() public {
+        _removeMinter(msg.sender);
+    }
 
-  function _addMinter(address account) internal {
-    minters.add(account);
-    emit MinterAdded(account);
-  }
+    function _addMinter(address account) internal {
+        _minters.add(account);
+        emit MinterAdded(account);
+    }
 
-  function _removeMinter(address account) internal {
-    minters.remove(account);
-    emit MinterRemoved(account);
-  }
+    function _removeMinter(address account) internal {
+        _minters.remove(account);
+        emit MinterRemoved(account);
+    }
 }

contracts/access/roles/PauserRole.sol

@@ -1,43 +1,43 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../Roles.sol";
 
 contract PauserRole {
-  using Roles for Roles.Role;
+    using Roles for Roles.Role;
 
-  event PauserAdded(address indexed account);
-  event PauserRemoved(address indexed account);
+    event PauserAdded(address indexed account);
+    event PauserRemoved(address indexed account);
 
-  Roles.Role private pausers;
+    Roles.Role private _pausers;
 
-  constructor() internal {
-    _addPauser(msg.sender);
-  }
+    constructor () internal {
+        _addPauser(msg.sender);
+    }
 
-  modifier onlyPauser() {
-    require(isPauser(msg.sender));
-    _;
-  }
+    modifier onlyPauser() {
+        require(isPauser(msg.sender));
+        _;
+    }
 
-  function isPauser(address account) public view returns (bool) {
-    return pausers.has(account);
-  }
+    function isPauser(address account) public view returns (bool) {
+        return _pausers.has(account);
+    }
 
-  function addPauser(address account) public onlyPauser {
-    _addPauser(account);
-  }
+    function addPauser(address account) public onlyPauser {
+        _addPauser(account);
+    }
 
-  function renouncePauser() public {
-    _removePauser(msg.sender);
-  }
+    function renouncePauser() public {
+        _removePauser(msg.sender);
+    }
 
-  function _addPauser(address account) internal {
-    pausers.add(account);
-    emit PauserAdded(account);
-  }
+    function _addPauser(address account) internal {
+        _pausers.add(account);
+        emit PauserAdded(account);
+    }
 
-  function _removePauser(address account) internal {
-    pausers.remove(account);
-    emit PauserRemoved(account);
-  }
+    function _removePauser(address account) internal {
+        _pausers.remove(account);
+        emit PauserRemoved(account);
+    }
 }

contracts/access/roles/SignerRole.sol

@@ -1,43 +1,43 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../Roles.sol";
 
 contract SignerRole {
-  using Roles for Roles.Role;
+    using Roles for Roles.Role;
 
-  event SignerAdded(address indexed account);
-  event SignerRemoved(address indexed account);
+    event SignerAdded(address indexed account);
+    event SignerRemoved(address indexed account);
 
-  Roles.Role private signers;
+    Roles.Role private _signers;
 
-  constructor() internal {
-    _addSigner(msg.sender);
-  }
+    constructor () internal {
+        _addSigner(msg.sender);
+    }
 
-  modifier onlySigner() {
-    require(isSigner(msg.sender));
-    _;
-  }
+    modifier onlySigner() {
+        require(isSigner(msg.sender));
+        _;
+    }
 
-  function isSigner(address account) public view returns (bool) {
-    return signers.has(account);
-  }
+    function isSigner(address account) public view returns (bool) {
+        return _signers.has(account);
+    }
 
-  function addSigner(address account) public onlySigner {
-    _addSigner(account);
-  }
+    function addSigner(address account) public onlySigner {
+        _addSigner(account);
+    }
 
-  function renounceSigner() public {
-    _removeSigner(msg.sender);
-  }
+    function renounceSigner() public {
+        _removeSigner(msg.sender);
+    }
 
-  function _addSigner(address account) internal {
-    signers.add(account);
-    emit SignerAdded(account);
-  }
+    function _addSigner(address account) internal {
+        _signers.add(account);
+        emit SignerAdded(account);
+    }
 
-  function _removeSigner(address account) internal {
-    signers.remove(account);
-    emit SignerRemoved(account);
-  }
+    function _removeSigner(address account) internal {
+        _signers.remove(account);
+        emit SignerRemoved(account);
+    }
 }

contracts/access/roles/WhitelistAdminRole.sol

@@ -0,0 +1,47 @@
+pragma solidity ^0.5.0;
+
+import "../Roles.sol";
+
+/**
+ * @title WhitelistAdminRole
+ * @dev WhitelistAdmins are responsible for assigning and removing Whitelisted accounts.
+ */
+contract WhitelistAdminRole {
+    using Roles for Roles.Role;
+
+    event WhitelistAdminAdded(address indexed account);
+    event WhitelistAdminRemoved(address indexed account);
+
+    Roles.Role private _whitelistAdmins;
+
+    constructor () internal {
+        _addWhitelistAdmin(msg.sender);
+    }
+
+    modifier onlyWhitelistAdmin() {
+        require(isWhitelistAdmin(msg.sender));
+        _;
+    }
+
+    function isWhitelistAdmin(address account) public view returns (bool) {
+        return _whitelistAdmins.has(account);
+    }
+
+    function addWhitelistAdmin(address account) public onlyWhitelistAdmin {
+        _addWhitelistAdmin(account);
+    }
+
+    function renounceWhitelistAdmin() public {
+        _removeWhitelistAdmin(msg.sender);
+    }
+
+    function _addWhitelistAdmin(address account) internal {
+        _whitelistAdmins.add(account);
+        emit WhitelistAdminAdded(account);
+    }
+
+    function _removeWhitelistAdmin(address account) internal {
+        _whitelistAdmins.remove(account);
+        emit WhitelistAdminRemoved(account);
+    }
+}

contracts/access/roles/WhitelistedRole.sol

@@ -0,0 +1,50 @@
+pragma solidity ^0.5.0;
+
+import "../Roles.sol";
+import "./WhitelistAdminRole.sol";
+
+/**
+ * @title WhitelistedRole
+ * @dev Whitelisted accounts have been approved by a WhitelistAdmin to perform certain actions (e.g. participate in a
+ * crowdsale). This role is special in that the only accounts that can add it are WhitelistAdmins (who can also remove
+ * it), and not Whitelisteds themselves.
+ */
+contract WhitelistedRole is WhitelistAdminRole {
+    using Roles for Roles.Role;
+
+    event WhitelistedAdded(address indexed account);
+    event WhitelistedRemoved(address indexed account);
+
+    Roles.Role private _whitelisteds;
+
+    modifier onlyWhitelisted() {
+        require(isWhitelisted(msg.sender));
+        _;
+    }
+
+    function isWhitelisted(address account) public view returns (bool) {
+        return _whitelisteds.has(account);
+    }
+
+    function addWhitelisted(address account) public onlyWhitelistAdmin {
+        _addWhitelisted(account);
+    }
+
+    function removeWhitelisted(address account) public onlyWhitelistAdmin {
+        _removeWhitelisted(account);
+    }
+
+    function renounceWhitelisted() public {
+        _removeWhitelisted(msg.sender);
+    }
+
+    function _addWhitelisted(address account) internal {
+        _whitelisteds.add(account);
+        emit WhitelistedAdded(account);
+    }
+
+    function _removeWhitelisted(address account) internal {
+        _whitelisteds.remove(account);
+        emit WhitelistedRemoved(account);
+    }
+}

contracts/crowdsale/Crowdsale.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/IERC20.sol";
 import "../math/SafeMath.sol";
@@ -18,224 +18,181 @@ import "../utils/ReentrancyGuard.sol";
  * behavior.
  */
 contract Crowdsale is ReentrancyGuard {
-  using SafeMath for uint256;
-  using SafeERC20 for IERC20;
+    using SafeMath for uint256;
+    using SafeERC20 for IERC20;
 
-  // The token being sold
-  IERC20 private _token;
+    // The token being sold
+    IERC20 private _token;
 
-  // Address where funds are collected
-  address private _wallet;
+    // Address where funds are collected
+    address payable private _wallet;
 
-  // How many token units a buyer gets per wei.
-  // The rate is the conversion between wei and the smallest and indivisible token unit.
-  // So, if you are using a rate of 1 with a ERC20Detailed token with 3 decimals called TOK
-  // 1 wei will give you 1 unit, or 0.001 TOK.
-  uint256 private _rate;
+    // How many token units a buyer gets per wei.
+    // The rate is the conversion between wei and the smallest and indivisible token unit.
+    // So, if you are using a rate of 1 with a ERC20Detailed token with 3 decimals called TOK
+    // 1 wei will give you 1 unit, or 0.001 TOK.
+    uint256 private _rate;
 
-  // Amount of wei raised
-  uint256 private _weiRaised;
+    // Amount of wei raised
+    uint256 private _weiRaised;
 
-  /**
-   * Event for token purchase logging
-   * @param purchaser who paid for the tokens
-   * @param beneficiary who got the tokens
-   * @param value weis paid for purchase
-   * @param amount amount of tokens purchased
-   */
-  event TokensPurchased(
-    address indexed purchaser,
-    address indexed beneficiary,
-    uint256 value,
-    uint256 amount
-  );
+    /**
+     * Event for token purchase logging
+     * @param purchaser who paid for the tokens
+     * @param beneficiary who got the tokens
+     * @param value weis paid for purchase
+     * @param amount amount of tokens purchased
+     */
+    event TokensPurchased(address indexed purchaser, address indexed beneficiary, uint256 value, uint256 amount);
 
-  /**
-   * @param rate Number of token units a buyer gets per wei
-   * @dev The rate is the conversion between wei and the smallest and indivisible
-   * token unit. So, if you are using a rate of 1 with a ERC20Detailed token
-   * with 3 decimals called TOK, 1 wei will give you 1 unit, or 0.001 TOK.
-   * @param wallet Address where collected funds will be forwarded to
-   * @param token Address of the token being sold
-   */
-  constructor(uint256 rate, address wallet, IERC20 token) internal {
-    require(rate > 0);
-    require(wallet != address(0));
-    require(token != address(0));
+    /**
+     * @param rate Number of token units a buyer gets per wei
+     * @dev The rate is the conversion between wei and the smallest and indivisible
+     * token unit. So, if you are using a rate of 1 with a ERC20Detailed token
+     * with 3 decimals called TOK, 1 wei will give you 1 unit, or 0.001 TOK.
+     * @param wallet Address where collected funds will be forwarded to
+     * @param token Address of the token being sold
+     */
+    constructor (uint256 rate, address payable wallet, IERC20 token) public {
+        require(rate > 0);
+        require(wallet != address(0));
+        require(address(token) != address(0));
 
-    _rate = rate;
-    _wallet = wallet;
-    _token = token;
-  }
+        _rate = rate;
+        _wallet = wallet;
+        _token = token;
+    }
 
-  // -----------------------------------------
-  // Crowdsale external interface
-  // -----------------------------------------
+    /**
+     * @dev fallback function ***DO NOT OVERRIDE***
+     * Note that other contracts will transfer fund with a base gas stipend
+     * of 2300, which is not enough to call buyTokens. Consider calling
+     * buyTokens directly when purchasing tokens from a contract.
+     */
+    function () external payable {
+        buyTokens(msg.sender);
+    }
 
-  /**
-   * @dev fallback function ***DO NOT OVERRIDE***
-   * Note that other contracts will transfer fund with a base gas stipend
-   * of 2300, which is not enough to call buyTokens. Consider calling
-   * buyTokens directly when purchasing tokens from a contract.
-   */
-  function () external payable {
-    buyTokens(msg.sender);
-  }
+    /**
+     * @return the token being sold.
+     */
+    function token() public view returns (IERC20) {
+        return _token;
+    }
 
-  /**
-   * @return the token being sold.
-   */
-  function token() public view returns(IERC20) {
-    return _token;
-  }
+    /**
+     * @return the address where funds are collected.
+     */
+    function wallet() public view returns (address payable) {
+        return _wallet;
+    }
 
-  /**
-   * @return the address where funds are collected.
-   */
-  function wallet() public view returns(address) {
-    return _wallet;
-  }
+    /**
+     * @return the number of token units a buyer gets per wei.
+     */
+    function rate() public view returns (uint256) {
+        return _rate;
+    }
 
-  /**
-   * @return the number of token units a buyer gets per wei.
-   */
-  function rate() public view returns(uint256) {
-    return _rate;
-  }
+    /**
+     * @return the amount of wei raised.
+     */
+    function weiRaised() public view returns (uint256) {
+        return _weiRaised;
+    }
 
-  /**
-   * @return the amount of wei raised.
-   */
-  function weiRaised() public view returns (uint256) {
-    return _weiRaised;
-  }
+    /**
+     * @dev low level token purchase ***DO NOT OVERRIDE***
+     * This function has a non-reentrancy guard, so it shouldn't be called by
+     * another `nonReentrant` function.
+     * @param beneficiary Recipient of the token purchase
+     */
+    function buyTokens(address beneficiary) public nonReentrant payable {
+        uint256 weiAmount = msg.value;
+        _preValidatePurchase(beneficiary, weiAmount);
 
-  /**
-   * @dev low level token purchase ***DO NOT OVERRIDE***
-   * This function has a non-reentrancy guard, so it shouldn't be called by
-   * another `nonReentrant` function.
-   * @param beneficiary Recipient of the token purchase
-   */
-  function buyTokens(address beneficiary) public nonReentrant payable {
+        // calculate token amount to be created
+        uint256 tokens = _getTokenAmount(weiAmount);
 
-    uint256 weiAmount = msg.value;
-    _preValidatePurchase(beneficiary, weiAmount);
+        // update state
+        _weiRaised = _weiRaised.add(weiAmount);
 
-    // calculate token amount to be created
-    uint256 tokens = _getTokenAmount(weiAmount);
+        _processPurchase(beneficiary, tokens);
+        emit TokensPurchased(msg.sender, beneficiary, weiAmount, tokens);
 
-    // update state
-    _weiRaised = _weiRaised.add(weiAmount);
+        _updatePurchasingState(beneficiary, weiAmount);
 
-    _processPurchase(beneficiary, tokens);
-    emit TokensPurchased(
-      msg.sender,
-      beneficiary,
-      weiAmount,
-      tokens
-    );
+        _forwardFunds();
+        _postValidatePurchase(beneficiary, weiAmount);
+    }
 
-    _updatePurchasingState(beneficiary, weiAmount);
+    /**
+     * @dev Validation of an incoming purchase. Use require statements to revert state when conditions are not met.
+     * Use `super` in contracts that inherit from Crowdsale to extend their validations.
+     * Example from CappedCrowdsale.sol's _preValidatePurchase method:
+     *     super._preValidatePurchase(beneficiary, weiAmount);
+     *     require(weiRaised().add(weiAmount) <= cap);
+     * @param beneficiary Address performing the token purchase
+     * @param weiAmount Value in wei involved in the purchase
+     */
+    function _preValidatePurchase(address beneficiary, uint256 weiAmount) internal view {
+        require(beneficiary != address(0));
+        require(weiAmount != 0);
+    }
 
-    _forwardFunds();
-    _postValidatePurchase(beneficiary, weiAmount);
-  }
+    /**
+     * @dev Validation of an executed purchase. Observe state and use revert statements to undo rollback when valid
+     * conditions are not met.
+     * @param beneficiary Address performing the token purchase
+     * @param weiAmount Value in wei involved in the purchase
+     */
+    function _postValidatePurchase(address beneficiary, uint256 weiAmount) internal view {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 
-  // -----------------------------------------
-  // Internal interface (extensible)
-  // -----------------------------------------
+    /**
+     * @dev Source of tokens. Override this method to modify the way in which the crowdsale ultimately gets and sends
+     * its tokens.
+     * @param beneficiary Address performing the token purchase
+     * @param tokenAmount Number of tokens to be emitted
+     */
+    function _deliverTokens(address beneficiary, uint256 tokenAmount) internal {
+        _token.safeTransfer(beneficiary, tokenAmount);
+    }
 
-  /**
-   * @dev Validation of an incoming purchase. Use require statements to revert state when conditions are not met. Use `super` in contracts that inherit from Crowdsale to extend their validations.
-   * Example from CappedCrowdsale.sol's _preValidatePurchase method:
-   *   super._preValidatePurchase(beneficiary, weiAmount);
-   *   require(weiRaised().add(weiAmount) <= cap);
-   * @param beneficiary Address performing the token purchase
-   * @param weiAmount Value in wei involved in the purchase
-   */
-  function _preValidatePurchase(
-    address beneficiary,
-    uint256 weiAmount
-  )
-    internal
-    view
-  {
-    require(beneficiary != address(0));
-    require(weiAmount != 0);
-  }
+    /**
+     * @dev Executed when a purchase has been validated and is ready to be executed. Doesn't necessarily emit/send
+     * tokens.
+     * @param beneficiary Address receiving the tokens
+     * @param tokenAmount Number of tokens to be purchased
+     */
+    function _processPurchase(address beneficiary, uint256 tokenAmount) internal {
+        _deliverTokens(beneficiary, tokenAmount);
+    }
 
-  /**
-   * @dev Validation of an executed purchase. Observe state and use revert statements to undo rollback when valid conditions are not met.
-   * @param beneficiary Address performing the token purchase
-   * @param weiAmount Value in wei involved in the purchase
-   */
-  function _postValidatePurchase(
-    address beneficiary,
-    uint256 weiAmount
-  )
-    internal
-    view
-  {
-    // optional override
-  }
+    /**
+     * @dev Override for extensions that require an internal state to check for validity (current user contributions,
+     * etc.)
+     * @param beneficiary Address receiving the tokens
+     * @param weiAmount Value in wei involved in the purchase
+     */
+    function _updatePurchasingState(address beneficiary, uint256 weiAmount) internal {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 
-  /**
-   * @dev Source of tokens. Override this method to modify the way in which the crowdsale ultimately gets and sends its tokens.
-   * @param beneficiary Address performing the token purchase
-   * @param tokenAmount Number of tokens to be emitted
-   */
-  function _deliverTokens(
-    address beneficiary,
-    uint256 tokenAmount
-  )
-    internal
-  {
-    _token.safeTransfer(beneficiary, tokenAmount);
-  }
+    /**
+     * @dev Override to extend the way in which ether is converted to tokens.
+     * @param weiAmount Value in wei to be converted into tokens
+     * @return Number of tokens that can be purchased with the specified _weiAmount
+     */
+    function _getTokenAmount(uint256 weiAmount) internal view returns (uint256) {
+        return weiAmount.mul(_rate);
+    }
 
-  /**
-   * @dev Executed when a purchase has been validated and is ready to be executed. Doesn't necessarily emit/send tokens.
-   * @param beneficiary Address receiving the tokens
-   * @param tokenAmount Number of tokens to be purchased
-   */
-  function _processPurchase(
-    address beneficiary,
-    uint256 tokenAmount
-  )
-    internal
-  {
-    _deliverTokens(beneficiary, tokenAmount);
-  }
-
-  /**
-   * @dev Override for extensions that require an internal state to check for validity (current user contributions, etc.)
-   * @param beneficiary Address receiving the tokens
-   * @param weiAmount Value in wei involved in the purchase
-   */
-  function _updatePurchasingState(
-    address beneficiary,
-    uint256 weiAmount
-  )
-    internal
-  {
-    // optional override
-  }
-
-  /**
-   * @dev Override to extend the way in which ether is converted to tokens.
-   * @param weiAmount Value in wei to be converted into tokens
-   * @return Number of tokens that can be purchased with the specified _weiAmount
-   */
-  function _getTokenAmount(uint256 weiAmount)
-    internal view returns (uint256)
-  {
-    return weiAmount.mul(_rate);
-  }
-
-  /**
-   * @dev Determines how ETH is stored/forwarded on purchases.
-   */
-  function _forwardFunds() internal {
-    _wallet.transfer(msg.value);
-  }
+    /**
+     * @dev Determines how ETH is stored/forwarded on purchases.
+     */
+    function _forwardFunds() internal {
+        _wallet.transfer(msg.value);
+    }
 }

contracts/crowdsale/distribution/FinalizableCrowdsale.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../../math/SafeMath.sol";
 import "../validation/TimedCrowdsale.sol";
@@ -9,42 +9,43 @@ import "../validation/TimedCrowdsale.sol";
  * can do extra work after finishing.
  */
 contract FinalizableCrowdsale is TimedCrowdsale {
-  using SafeMath for uint256;
+    using SafeMath for uint256;
 
-  bool private _finalized;
+    bool private _finalized;
 
-  event CrowdsaleFinalized();
+    event CrowdsaleFinalized();
 
-  constructor() internal {
-    _finalized = false;
-  }
+    constructor () internal {
+        _finalized = false;
+    }
 
-  /**
-   * @return true if the crowdsale is finalized, false otherwise.
-   */
-  function finalized() public view returns (bool) {
-    return _finalized;
-  }
+    /**
+     * @return true if the crowdsale is finalized, false otherwise.
+     */
+    function finalized() public view returns (bool) {
+        return _finalized;
+    }
 
-  /**
-   * @dev Must be called after crowdsale ends, to do some extra finalization
-   * work. Calls the contract's finalization function.
-   */
-  function finalize() public {
-    require(!_finalized);
-    require(hasClosed());
+    /**
+     * @dev Must be called after crowdsale ends, to do some extra finalization
+     * work. Calls the contract's finalization function.
+     */
+    function finalize() public {
+        require(!_finalized);
+        require(hasClosed());
 
-    _finalized = true;
+        _finalized = true;
 
-    _finalization();
-    emit CrowdsaleFinalized();
-  }
+        _finalization();
+        emit CrowdsaleFinalized();
+    }
 
-  /**
-   * @dev Can be overridden to add finalization logic. The overriding function
-   * should call super._finalization() to ensure the chain of finalization is
-   * executed entirely.
-   */
-  function _finalization() internal {
-  }
+    /**
+     * @dev Can be overridden to add finalization logic. The overriding function
+     * should call super._finalization() to ensure the chain of finalization is
+     * executed entirely.
+     */
+    function _finalization() internal {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 }

contracts/crowdsale/distribution/PostDeliveryCrowdsale.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../validation/TimedCrowdsale.sol";
 import "../../math/SafeMath.sol";
@@ -8,43 +8,36 @@ import "../../math/SafeMath.sol";
  * @dev Crowdsale that locks tokens from withdrawal until it ends.
  */
 contract PostDeliveryCrowdsale is TimedCrowdsale {
-  using SafeMath for uint256;
+    using SafeMath for uint256;
 
-  mapping(address => uint256) private _balances;
+    mapping(address => uint256) private _balances;
 
-  constructor() internal {}
+    /**
+     * @dev Withdraw tokens only after crowdsale ends.
+     * @param beneficiary Whose tokens will be withdrawn.
+     */
+    function withdrawTokens(address beneficiary) public {
+        require(hasClosed());
+        uint256 amount = _balances[beneficiary];
+        require(amount > 0);
+        _balances[beneficiary] = 0;
+        _deliverTokens(beneficiary, amount);
+    }
 
-  /**
-   * @dev Withdraw tokens only after crowdsale ends.
-   * @param beneficiary Whose tokens will be withdrawn.
-   */
-  function withdrawTokens(address beneficiary) public {
-    require(hasClosed());
-    uint256 amount = _balances[beneficiary];
-    require(amount > 0);
-    _balances[beneficiary] = 0;
-    _deliverTokens(beneficiary, amount);
-  }
+    /**
+     * @return the balance of an account.
+     */
+    function balanceOf(address account) public view returns (uint256) {
+        return _balances[account];
+    }
 
-  /**
-   * @return the balance of an account.
-   */
-  function balanceOf(address account) public view returns(uint256) {
-    return _balances[account];
-  }
-
-  /**
-   * @dev Overrides parent by storing balances instead of issuing tokens right away.
-   * @param beneficiary Token purchaser
-   * @param tokenAmount Amount of tokens purchased
-   */
-  function _processPurchase(
-    address beneficiary,
-    uint256 tokenAmount
-  )
-    internal
-  {
-    _balances[beneficiary] = _balances[beneficiary].add(tokenAmount);
-  }
+    /**
+     * @dev Overrides parent by storing balances instead of issuing tokens right away.
+     * @param beneficiary Token purchaser
+     * @param tokenAmount Amount of tokens purchased
+     */
+    function _processPurchase(address beneficiary, uint256 tokenAmount) internal {
+        _balances[beneficiary] = _balances[beneficiary].add(tokenAmount);
+    }
 
 }

contracts/crowdsale/distribution/RefundableCrowdsale.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../../math/SafeMath.sol";
 import "./FinalizableCrowdsale.sol";
@@ -6,86 +6,77 @@ import "../../payment/escrow/RefundEscrow.sol";
 
 /**
  * @title RefundableCrowdsale
- * @dev Extension of Crowdsale contract that adds a funding goal, and
- * the possibility of users getting a refund if goal is not met.
- * WARNING: note that if you allow tokens to be traded before the goal 
- * is met, then an attack is possible in which the attacker purchases 
- * tokens from the crowdsale and when they sees that the goal is 
- * unlikely to be met, they sell their tokens (possibly at a discount).
- * The attacker will be refunded when the crowdsale is finalized, and
- * the users that purchased from them will be left with worthless 
- * tokens. There are many possible ways to avoid this, like making the
- * the crowdsale inherit from PostDeliveryCrowdsale, or imposing 
- * restrictions on token trading until the crowdsale is finalized.
- * This is being discussed in 
- * https://github.com/OpenZeppelin/openzeppelin-solidity/issues/877
- * This contract will be updated when we agree on a general solution
- * for this problem.
+ * @dev Extension of Crowdsale contract that adds a funding goal, and the possibility of users getting a refund if goal
+ * is not met.
+ *
+ * Deprecated, use RefundablePostDeliveryCrowdsale instead. Note that if you allow tokens to be traded before the goal
+ * is met, then an attack is possible in which the attacker purchases tokens from the crowdsale and when they sees that
+ * the goal is unlikely to be met, they sell their tokens (possibly at a discount). The attacker will be refunded when
+ * the crowdsale is finalized, and the users that purchased from them will be left with worthless tokens.
  */
 contract RefundableCrowdsale is FinalizableCrowdsale {
-  using SafeMath for uint256;
+    using SafeMath for uint256;
 
-  // minimum amount of funds to be raised in weis
-  uint256 private _goal;
+    // minimum amount of funds to be raised in weis
+    uint256 private _goal;
 
-  // refund escrow used to hold funds while crowdsale is running
-  RefundEscrow private _escrow;
+    // refund escrow used to hold funds while crowdsale is running
+    RefundEscrow private _escrow;
 
-  /**
-   * @dev Constructor, creates RefundEscrow.
-   * @param goal Funding goal
-   */
-  constructor(uint256 goal) internal {
-    require(goal > 0);
-    _escrow = new RefundEscrow(wallet());
-    _goal = goal;
-  }
-
-  /**
-   * @return minimum amount of funds to be raised in wei.
-   */
-  function goal() public view returns(uint256) {
-    return _goal;
-  }
-
-  /**
-   * @dev Investors can claim refunds here if crowdsale is unsuccessful
-   * @param beneficiary Whose refund will be claimed.
-   */
-  function claimRefund(address beneficiary) public {
-    require(finalized());
-    require(!goalReached());
-
-    _escrow.withdraw(beneficiary);
-  }
-
-  /**
-   * @dev Checks whether funding goal was reached.
-   * @return Whether funding goal was reached
-   */
-  function goalReached() public view returns (bool) {
-    return weiRaised() >= _goal;
-  }
-
-  /**
-   * @dev escrow finalization task, called when finalize() is called
-   */
-  function _finalization() internal {
-    if (goalReached()) {
-      _escrow.close();
-      _escrow.beneficiaryWithdraw();
-    } else {
-      _escrow.enableRefunds();
+    /**
+     * @dev Constructor, creates RefundEscrow.
+     * @param goal Funding goal
+     */
+    constructor (uint256 goal) public {
+        require(goal > 0);
+        _escrow = new RefundEscrow(wallet());
+        _goal = goal;
     }
 
-    super._finalization();
-  }
+    /**
+     * @return minimum amount of funds to be raised in wei.
+     */
+    function goal() public view returns (uint256) {
+        return _goal;
+    }
 
-  /**
-   * @dev Overrides Crowdsale fund forwarding, sending funds to escrow.
-   */
-  function _forwardFunds() internal {
-    _escrow.deposit.value(msg.value)(msg.sender);
-  }
+    /**
+     * @dev Investors can claim refunds here if crowdsale is unsuccessful
+     * @param refundee Whose refund will be claimed.
+     */
+    function claimRefund(address payable refundee) public {
+        require(finalized());
+        require(!goalReached());
 
+        _escrow.withdraw(refundee);
+    }
+
+    /**
+     * @dev Checks whether funding goal was reached.
+     * @return Whether funding goal was reached
+     */
+    function goalReached() public view returns (bool) {
+        return weiRaised() >= _goal;
+    }
+
+    /**
+     * @dev escrow finalization task, called when finalize() is called
+     */
+    function _finalization() internal {
+        if (goalReached()) {
+            _escrow.close();
+            _escrow.beneficiaryWithdraw();
+        } else {
+            _escrow.enableRefunds();
+        }
+
+        super._finalization();
+    }
+
+    /**
+     * @dev Overrides Crowdsale fund forwarding, sending funds to escrow.
+     */
+    function _forwardFunds() internal {
+        _escrow.deposit.value(msg.value)(msg.sender);
+    }
 }

contracts/crowdsale/distribution/RefundablePostDeliveryCrowdsale.sol

@@ -0,0 +1,20 @@
+pragma solidity ^0.5.0;
+
+import "./RefundableCrowdsale.sol";
+import "./PostDeliveryCrowdsale.sol";
+
+
+/**
+ * @title RefundablePostDeliveryCrowdsale
+ * @dev Extension of RefundableCrowdsale contract that only delivers the tokens
+ * once the crowdsale has closed and the goal met, preventing refunds to be issued
+ * to token holders.
+ */
+contract RefundablePostDeliveryCrowdsale is RefundableCrowdsale, PostDeliveryCrowdsale {
+    function withdrawTokens(address beneficiary) public {
+        require(finalized());
+        require(goalReached());
+
+        super.withdrawTokens(beneficiary);
+    }
+}

contracts/crowdsale/emission/AllowanceCrowdsale.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../Crowdsale.sol";
 import "../../token/ERC20/IERC20.sol";
@@ -11,49 +11,41 @@ import "../../math/Math.sol";
  * @dev Extension of Crowdsale where tokens are held by a wallet, which approves an allowance to the crowdsale.
  */
 contract AllowanceCrowdsale is Crowdsale {
-  using SafeMath for uint256;
-  using SafeERC20 for IERC20;
+    using SafeMath for uint256;
+    using SafeERC20 for IERC20;
 
-  address private _tokenWallet;
+    address private _tokenWallet;
 
-  /**
-   * @dev Constructor, takes token wallet address.
-   * @param tokenWallet Address holding the tokens, which has approved allowance to the crowdsale
-   */
-  constructor(address tokenWallet) internal {
-    require(tokenWallet != address(0));
-    _tokenWallet = tokenWallet;
-  }
+    /**
+     * @dev Constructor, takes token wallet address.
+     * @param tokenWallet Address holding the tokens, which has approved allowance to the crowdsale
+     */
+    constructor (address tokenWallet) public {
+        require(tokenWallet != address(0));
+        _tokenWallet = tokenWallet;
+    }
 
-  /**
-   * @return the address of the wallet that will hold the tokens.
-   */
-  function tokenWallet() public view returns(address) {
-    return _tokenWallet;
-  }
+    /**
+     * @return the address of the wallet that will hold the tokens.
+     */
+    function tokenWallet() public view returns (address) {
+        return _tokenWallet;
+    }
 
-  /**
-   * @dev Checks the amount of tokens left in the allowance.
-   * @return Amount of tokens left in the allowance
-   */
-  function remainingTokens() public view returns (uint256) {
-    return Math.min(
-      token().balanceOf(_tokenWallet),
-      token().allowance(_tokenWallet, this)
-    );
-  }
+    /**
+     * @dev Checks the amount of tokens left in the allowance.
+     * @return Amount of tokens left in the allowance
+     */
+    function remainingTokens() public view returns (uint256) {
+        return Math.min(token().balanceOf(_tokenWallet), token().allowance(_tokenWallet, address(this)));
+    }
 
-  /**
-   * @dev Overrides parent behavior by transferring tokens from wallet.
-   * @param beneficiary Token purchaser
-   * @param tokenAmount Amount of tokens purchased
-   */
-  function _deliverTokens(
-    address beneficiary,
-    uint256 tokenAmount
-  )
-    internal
-  {
-    token().safeTransferFrom(_tokenWallet, beneficiary, tokenAmount);
-  }
+    /**
+     * @dev Overrides parent behavior by transferring tokens from wallet.
+     * @param beneficiary Token purchaser
+     * @param tokenAmount Amount of tokens purchased
+     */
+    function _deliverTokens(address beneficiary, uint256 tokenAmount) internal {
+        token().safeTransferFrom(_tokenWallet, beneficiary, tokenAmount);
+    }
 }

contracts/crowdsale/emission/MintedCrowdsale.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../Crowdsale.sol";
 import "../../token/ERC20/ERC20Mintable.sol";
@@ -9,21 +9,13 @@ import "../../token/ERC20/ERC20Mintable.sol";
  * Token ownership should be transferred to MintedCrowdsale for minting.
  */
 contract MintedCrowdsale is Crowdsale {
-  constructor() internal {}
-
-  /**
-   * @dev Overrides delivery by minting tokens upon purchase.
-   * @param beneficiary Token purchaser
-   * @param tokenAmount Number of tokens to be minted
-   */
-  function _deliverTokens(
-    address beneficiary,
-    uint256 tokenAmount
-  )
-    internal
-  {
-    // Potentially dangerous assumption about the type of the token.
-    require(
-      ERC20Mintable(address(token())).mint(beneficiary, tokenAmount));
-  }
+    /**
+     * @dev Overrides delivery by minting tokens upon purchase.
+     * @param beneficiary Token purchaser
+     * @param tokenAmount Number of tokens to be minted
+     */
+    function _deliverTokens(address beneficiary, uint256 tokenAmount) internal {
+        // Potentially dangerous assumption about the type of the token.
+        require(ERC20Mintable(address(token())).mint(beneficiary, tokenAmount));
+    }
 }

contracts/crowdsale/price/IncreasingPriceCrowdsale.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../validation/TimedCrowdsale.sol";
 import "../../math/SafeMath.sol";
@@ -10,72 +10,69 @@ import "../../math/SafeMath.sol";
  * the amount of tokens per wei contributed. Thus, the initial rate must be greater than the final rate.
  */
 contract IncreasingPriceCrowdsale is TimedCrowdsale {
-  using SafeMath for uint256;
+    using SafeMath for uint256;
 
-  uint256 private _initialRate;
-  uint256 private _finalRate;
+    uint256 private _initialRate;
+    uint256 private _finalRate;
 
-  /**
-   * @dev Constructor, takes initial and final rates of tokens received per wei contributed.
-   * @param initialRate Number of tokens a buyer gets per wei at the start of the crowdsale
-   * @param finalRate Number of tokens a buyer gets per wei at the end of the crowdsale
-   */
-  constructor(uint256 initialRate, uint256 finalRate) internal {
-    require(finalRate > 0);
-    require(initialRate > finalRate);
-    _initialRate = initialRate;
-    _finalRate = finalRate;
-  }
-
-  /**
-   * The base rate function is overridden to revert, since this crowdsale doens't use it, and
-   * all calls to it are a mistake.
-   */
-  function rate() public view returns(uint256) {
-    revert();
-  }
-
-  /**
-   * @return the initial rate of the crowdsale.
-   */
-  function initialRate() public view returns(uint256) {
-    return _initialRate;
-  }
-
-  /**
-   * @return the final rate of the crowdsale.
-   */
-  function finalRate() public view returns (uint256) {
-    return _finalRate;
-  }
-
-  /**
-   * @dev Returns the rate of tokens per wei at the present time.
-   * Note that, as price _increases_ with time, the rate _decreases_.
-   * @return The number of tokens a buyer gets per wei at a given time
-   */
-  function getCurrentRate() public view returns (uint256) {
-    if (!isOpen()) {
-      return 0;
+    /**
+     * @dev Constructor, takes initial and final rates of tokens received per wei contributed.
+     * @param initialRate Number of tokens a buyer gets per wei at the start of the crowdsale
+     * @param finalRate Number of tokens a buyer gets per wei at the end of the crowdsale
+     */
+    constructor (uint256 initialRate, uint256 finalRate) public {
+        require(finalRate > 0);
+        require(initialRate > finalRate);
+        _initialRate = initialRate;
+        _finalRate = finalRate;
     }
 
-    // solium-disable-next-line security/no-block-members
-    uint256 elapsedTime = block.timestamp.sub(openingTime());
-    uint256 timeRange = closingTime().sub(openingTime());
-    uint256 rateRange = _initialRate.sub(_finalRate);
-    return _initialRate.sub(elapsedTime.mul(rateRange).div(timeRange));
-  }
+    /**
+     * The base rate function is overridden to revert, since this crowdsale doens't use it, and
+     * all calls to it are a mistake.
+     */
+    function rate() public view returns (uint256) {
+        revert();
+    }
 
-  /**
-   * @dev Overrides parent method taking into account variable rate.
-   * @param weiAmount The value in wei to be converted into tokens
-   * @return The number of tokens _weiAmount wei will buy at present time
-   */
-  function _getTokenAmount(uint256 weiAmount)
-    internal view returns (uint256)
-  {
-    uint256 currentRate = getCurrentRate();
-    return currentRate.mul(weiAmount);
-  }
+    /**
+     * @return the initial rate of the crowdsale.
+     */
+    function initialRate() public view returns (uint256) {
+        return _initialRate;
+    }
 
+    /**
+     * @return the final rate of the crowdsale.
+     */
+    function finalRate() public view returns (uint256) {
+        return _finalRate;
+    }
+
+    /**
+     * @dev Returns the rate of tokens per wei at the present time.
+     * Note that, as price _increases_ with time, the rate _decreases_.
+     * @return The number of tokens a buyer gets per wei at a given time
+     */
+    function getCurrentRate() public view returns (uint256) {
+        if (!isOpen()) {
+            return 0;
+        }
+
+        // solhint-disable-next-line not-rely-on-time
+        uint256 elapsedTime = block.timestamp.sub(openingTime());
+        uint256 timeRange = closingTime().sub(openingTime());
+        uint256 rateRange = _initialRate.sub(_finalRate);
+        return _initialRate.sub(elapsedTime.mul(rateRange).div(timeRange));
+    }
+
+    /**
+     * @dev Overrides parent method taking into account variable rate.
+     * @param weiAmount The value in wei to be converted into tokens
+     * @return The number of tokens _weiAmount wei will buy at present time
+     */
+    function _getTokenAmount(uint256 weiAmount) internal view returns (uint256) {
+        uint256 currentRate = getCurrentRate();
+        return currentRate.mul(weiAmount);
+    }
 }

contracts/crowdsale/validation/CappedCrowdsale.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../../math/SafeMath.sol";
 import "../Crowdsale.sol";
@@ -8,48 +8,41 @@ import "../Crowdsale.sol";
  * @dev Crowdsale with a limit for total contributions.
  */
 contract CappedCrowdsale is Crowdsale {
-  using SafeMath for uint256;
+    using SafeMath for uint256;
 
-  uint256 private _cap;
+    uint256 private _cap;
 
-  /**
-   * @dev Constructor, takes maximum amount of wei accepted in the crowdsale.
-   * @param cap Max amount of wei to be contributed
-   */
-  constructor(uint256 cap) internal {
-    require(cap > 0);
-    _cap = cap;
-  }
+    /**
+     * @dev Constructor, takes maximum amount of wei accepted in the crowdsale.
+     * @param cap Max amount of wei to be contributed
+     */
+    constructor (uint256 cap) public {
+        require(cap > 0);
+        _cap = cap;
+    }
 
-  /**
-   * @return the cap of the crowdsale.
-   */
-  function cap() public view returns(uint256) {
-    return _cap;
-  }
+    /**
+     * @return the cap of the crowdsale.
+     */
+    function cap() public view returns (uint256) {
+        return _cap;
+    }
 
-  /**
-   * @dev Checks whether the cap has been reached.
-   * @return Whether the cap was reached
-   */
-  function capReached() public view returns (bool) {
-    return weiRaised() >= _cap;
-  }
-
-  /**
-   * @dev Extend parent behavior requiring purchase to respect the funding cap.
-   * @param beneficiary Token purchaser
-   * @param weiAmount Amount of wei contributed
-   */
-  function _preValidatePurchase(
-    address beneficiary,
-    uint256 weiAmount
-  )
-    internal
-    view
-  {
-    super._preValidatePurchase(beneficiary, weiAmount);
-    require(weiRaised().add(weiAmount) <= _cap);
-  }
+    /**
+     * @dev Checks whether the cap has been reached.
+     * @return Whether the cap was reached
+     */
+    function capReached() public view returns (bool) {
+        return weiRaised() >= _cap;
+    }
 
+    /**
+     * @dev Extend parent behavior requiring purchase to respect the funding cap.
+     * @param beneficiary Token purchaser
+     * @param weiAmount Amount of wei contributed
+     */
+    function _preValidatePurchase(address beneficiary, uint256 weiAmount) internal view {
+        super._preValidatePurchase(beneficiary, weiAmount);
+        require(weiRaised().add(weiAmount) <= _cap);
+    }
 }

contracts/crowdsale/validation/IndividuallyCappedCrowdsale.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../../math/SafeMath.sol";
 import "../Crowdsale.sol";
@@ -9,73 +9,55 @@ import "../../access/roles/CapperRole.sol";
  * @dev Crowdsale with per-beneficiary caps.
  */
 contract IndividuallyCappedCrowdsale is Crowdsale, CapperRole {
-  using SafeMath for uint256;
+    using SafeMath for uint256;
 
-  mapping(address => uint256) private _contributions;
-  mapping(address => uint256) private _caps;
+    mapping(address => uint256) private _contributions;
+    mapping(address => uint256) private _caps;
 
-  constructor() internal {}
+    /**
+     * @dev Sets a specific beneficiary's maximum contribution.
+     * @param beneficiary Address to be capped
+     * @param cap Wei limit for individual contribution
+     */
+    function setCap(address beneficiary, uint256 cap) external onlyCapper {
+        _caps[beneficiary] = cap;
+    }
 
-  /**
-   * @dev Sets a specific beneficiary's maximum contribution.
-   * @param beneficiary Address to be capped
-   * @param cap Wei limit for individual contribution
-   */
-  function setCap(address beneficiary, uint256 cap) external onlyCapper {
-    _caps[beneficiary] = cap;
-  }
+    /**
+     * @dev Returns the cap of a specific beneficiary.
+     * @param beneficiary Address whose cap is to be checked
+     * @return Current cap for individual beneficiary
+     */
+    function getCap(address beneficiary) public view returns (uint256) {
+        return _caps[beneficiary];
+    }
 
-  /**
-   * @dev Returns the cap of a specific beneficiary.
-   * @param beneficiary Address whose cap is to be checked
-   * @return Current cap for individual beneficiary
-   */
-  function getCap(address beneficiary) public view returns (uint256) {
-    return _caps[beneficiary];
-  }
+    /**
+     * @dev Returns the amount contributed so far by a specific beneficiary.
+     * @param beneficiary Address of contributor
+     * @return Beneficiary contribution so far
+     */
+    function getContribution(address beneficiary) public view returns (uint256) {
+        return _contributions[beneficiary];
+    }
 
-  /**
-   * @dev Returns the amount contributed so far by a specific beneficiary.
-   * @param beneficiary Address of contributor
-   * @return Beneficiary contribution so far
-   */
-  function getContribution(address beneficiary)
-    public view returns (uint256)
-  {
-    return _contributions[beneficiary];
-  }
-
-  /**
-   * @dev Extend parent behavior requiring purchase to respect the beneficiary's funding cap.
-   * @param beneficiary Token purchaser
-   * @param weiAmount Amount of wei contributed
-   */
-  function _preValidatePurchase(
-    address beneficiary,
-    uint256 weiAmount
-  )
-    internal
-    view
-  {
-    super._preValidatePurchase(beneficiary, weiAmount);
-    require(
-      _contributions[beneficiary].add(weiAmount) <= _caps[beneficiary]);
-  }
-
-  /**
-   * @dev Extend parent behavior to update beneficiary contributions
-   * @param beneficiary Token purchaser
-   * @param weiAmount Amount of wei contributed
-   */
-  function _updatePurchasingState(
-    address beneficiary,
-    uint256 weiAmount
-  )
-    internal
-  {
-    super._updatePurchasingState(beneficiary, weiAmount);
-    _contributions[beneficiary] = _contributions[beneficiary].add(
-      weiAmount);
-  }
+    /**
+     * @dev Extend parent behavior requiring purchase to respect the beneficiary's funding cap.
+     * @param beneficiary Token purchaser
+     * @param weiAmount Amount of wei contributed
+     */
+    function _preValidatePurchase(address beneficiary, uint256 weiAmount) internal view {
+        super._preValidatePurchase(beneficiary, weiAmount);
+        require(_contributions[beneficiary].add(weiAmount) <= _caps[beneficiary]);
+    }
 
+    /**
+     * @dev Extend parent behavior to update beneficiary contributions
+     * @param beneficiary Token purchaser
+     * @param weiAmount Amount of wei contributed
+     */
+    function _updatePurchasingState(address beneficiary, uint256 weiAmount) internal {
+        super._updatePurchasingState(beneficiary, weiAmount);
+        _contributions[beneficiary] = _contributions[beneficiary].add(weiAmount);
+    }
 }

contracts/crowdsale/validation/PausableCrowdsale.sol

@@ -0,0 +1,21 @@
+pragma solidity ^0.5.0;
+
+import "../Crowdsale.sol";
+import "../../lifecycle/Pausable.sol";
+
+/**
+ * @title PausableCrowdsale
+ * @dev Extension of Crowdsale contract where purchases can be paused and unpaused by the pauser role.
+ */
+contract PausableCrowdsale is Crowdsale, Pausable {
+    /**
+     * @dev Validation of an incoming purchase. Use require statements to revert state when conditions are not met.
+     * Use super to concatenate validations.
+     * Adds the validation that the crowdsale must not be paused.
+     * @param _beneficiary Address performing the token purchase
+     * @param _weiAmount Value in wei involved in the purchase
+     */
+    function _preValidatePurchase(address _beneficiary, uint256 _weiAmount) internal view whenNotPaused {
+        return super._preValidatePurchase(_beneficiary, _weiAmount);
+    }
+}

contracts/crowdsale/validation/TimedCrowdsale.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../../math/SafeMath.sol";
 import "../Crowdsale.sol";
@@ -8,78 +8,70 @@ import "../Crowdsale.sol";
  * @dev Crowdsale accepting contributions only within a time frame.
  */
 contract TimedCrowdsale is Crowdsale {
-  using SafeMath for uint256;
+    using SafeMath for uint256;
 
-  uint256 private _openingTime;
-  uint256 private _closingTime;
+    uint256 private _openingTime;
+    uint256 private _closingTime;
 
-  /**
-   * @dev Reverts if not in crowdsale time range.
-   */
-  modifier onlyWhileOpen {
-    require(isOpen());
-    _;
-  }
+    /**
+     * @dev Reverts if not in crowdsale time range.
+     */
+    modifier onlyWhileOpen {
+        require(isOpen());
+        _;
+    }
 
-  /**
-   * @dev Constructor, takes crowdsale opening and closing times.
-   * @param openingTime Crowdsale opening time
-   * @param closingTime Crowdsale closing time
-   */
-  constructor(uint256 openingTime, uint256 closingTime) internal {
-    // solium-disable-next-line security/no-block-members
-    require(openingTime >= block.timestamp);
-    require(closingTime > openingTime);
+    /**
+     * @dev Constructor, takes crowdsale opening and closing times.
+     * @param openingTime Crowdsale opening time
+     * @param closingTime Crowdsale closing time
+     */
+    constructor (uint256 openingTime, uint256 closingTime) public {
+        // solhint-disable-next-line not-rely-on-time
+        require(openingTime >= block.timestamp);
+        require(closingTime > openingTime);
 
-    _openingTime = openingTime;
-    _closingTime = closingTime;
-  }
+        _openingTime = openingTime;
+        _closingTime = closingTime;
+    }
 
-  /**
-   * @return the crowdsale opening time.
-   */
-  function openingTime() public view returns(uint256) {
-    return _openingTime;
-  }
+    /**
+     * @return the crowdsale opening time.
+     */
+    function openingTime() public view returns (uint256) {
+        return _openingTime;
+    }
 
-  /**
-   * @return the crowdsale closing time.
-   */
-  function closingTime() public view returns(uint256) {
-    return _closingTime;
-  }
+    /**
+     * @return the crowdsale closing time.
+     */
+    function closingTime() public view returns (uint256) {
+        return _closingTime;
+    }
 
-  /**
-   * @return true if the crowdsale is open, false otherwise.
-   */
-  function isOpen() public view returns (bool) {
-    // solium-disable-next-line security/no-block-members
-    return block.timestamp >= _openingTime && block.timestamp <= _closingTime;
-  }
+    /**
+     * @return true if the crowdsale is open, false otherwise.
+     */
+    function isOpen() public view returns (bool) {
+        // solhint-disable-next-line not-rely-on-time
+        return block.timestamp >= _openingTime && block.timestamp <= _closingTime;
+    }
 
-  /**
-   * @dev Checks whether the period in which the crowdsale is open has already elapsed.
-   * @return Whether crowdsale period has elapsed
-   */
-  function hasClosed() public view returns (bool) {
-    // solium-disable-next-line security/no-block-members
-    return block.timestamp > _closingTime;
-  }
-
-  /**
-   * @dev Extend parent behavior requiring to be within contributing period
-   * @param beneficiary Token purchaser
-   * @param weiAmount Amount of wei contributed
-   */
-  function _preValidatePurchase(
-    address beneficiary,
-    uint256 weiAmount
-  )
-    internal
-    onlyWhileOpen
-    view
-  {
-    super._preValidatePurchase(beneficiary, weiAmount);
-  }
+    /**
+     * @dev Checks whether the period in which the crowdsale is open has already elapsed.
+     * @return Whether crowdsale period has elapsed
+     */
+    function hasClosed() public view returns (bool) {
+        // solhint-disable-next-line not-rely-on-time
+        return block.timestamp > _closingTime;
+    }
 
+    /**
+     * @dev Extend parent behavior requiring to be within contributing period
+     * @param beneficiary Token purchaser
+     * @param weiAmount Amount of wei contributed
+     */
+    function _preValidatePurchase(address beneficiary, uint256 weiAmount) internal onlyWhileOpen view {
+        super._preValidatePurchase(beneficiary, weiAmount);
+    }
 }

contracts/crowdsale/validation/WhitelistCrowdsale.sol

@@ -0,0 +1,21 @@
+pragma solidity ^0.5.0;
+import "../Crowdsale.sol";
+import "../../access/roles/WhitelistedRole.sol";
+
+
+/**
+ * @title WhitelistCrowdsale
+ * @dev Crowdsale in which only whitelisted users can contribute.
+ */
+contract WhitelistCrowdsale is WhitelistedRole, Crowdsale {
+    /**
+    * @dev Extend parent behavior requiring beneficiary to be whitelisted. Note that no
+    * restriction is imposed on the account sending the transaction.
+    * @param _beneficiary Token beneficiary
+    * @param _weiAmount Amount of wei contributed
+    */
+    function _preValidatePurchase(address _beneficiary, uint256 _weiAmount) internal view {
+        require(isWhitelisted(_beneficiary));
+        super._preValidatePurchase(_beneficiary, _weiAmount);
+    }
+}

contracts/cryptography/ECDSA.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 /**
  * @title Elliptic curve signature operations
@@ -8,64 +8,52 @@ pragma solidity ^0.4.24;
  */
 
 library ECDSA {
+    /**
+     * @dev Recover signer address from a message by using their signature
+     * @param hash bytes32 message, the hash is the signed message. What is recovered is the signer address.
+     * @param signature bytes signature, the signature is generated using web3.eth.sign()
+     */
+    function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
+        bytes32 r;
+        bytes32 s;
+        uint8 v;
 
-  /**
-   * @dev Recover signer address from a message by using their signature
-   * @param hash bytes32 message, the hash is the signed message. What is recovered is the signer address.
-   * @param signature bytes signature, the signature is generated using web3.eth.sign()
-   */
-  function recover(bytes32 hash, bytes signature)
-    internal
-    pure
-    returns (address)
-  {
-    bytes32 r;
-    bytes32 s;
-    uint8 v;
+        // Check the signature length
+        if (signature.length != 65) {
+            return (address(0));
+        }
 
-    // Check the signature length
-    if (signature.length != 65) {
-      return (address(0));
+        // Divide the signature in r, s and v variables
+        // ecrecover takes the signature parameters, and the only way to get them
+        // currently is to use assembly.
+        // solhint-disable-next-line no-inline-assembly
+        assembly {
+            r := mload(add(signature, 0x20))
+            s := mload(add(signature, 0x40))
+            v := byte(0, mload(add(signature, 0x60)))
+        }
+
+        // Version of signature should be 27 or 28, but 0 and 1 are also possible versions
+        if (v < 27) {
+            v += 27;
+        }
+
+        // If the version is correct return the signer address
+        if (v != 27 && v != 28) {
+            return (address(0));
+        } else {
+            return ecrecover(hash, v, r, s);
+        }
     }
 
-    // Divide the signature in r, s and v variables
-    // ecrecover takes the signature parameters, and the only way to get them
-    // currently is to use assembly.
-    // solium-disable-next-line security/no-inline-assembly
-    assembly {
-      r := mload(add(signature, 0x20))
-      s := mload(add(signature, 0x40))
-      v := byte(0, mload(add(signature, 0x60)))
+    /**
+     * toEthSignedMessageHash
+     * @dev prefix a bytes32 value with "\x19Ethereum Signed Message:"
+     * and hash the result
+     */
+    function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
+        // 32 is the length in bytes of hash,
+        // enforced by the type signature above
+        return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", hash));
     }
-
-    // Version of signature should be 27 or 28, but 0 and 1 are also possible versions
-    if (v < 27) {
-      v += 27;
-    }
-
-    // If the version is correct return the signer address
-    if (v != 27 && v != 28) {
-      return (address(0));
-    } else {
-      // solium-disable-next-line arg-overflow
-      return ecrecover(hash, v, r, s);
-    }
-  }
-
-  /**
-   * toEthSignedMessageHash
-   * @dev prefix a bytes32 value with "\x19Ethereum Signed Message:"
-   * and hash the result
-   */
-  function toEthSignedMessageHash(bytes32 hash)
-    internal
-    pure
-    returns (bytes32)
-  {
-    // 32 is the length in bytes of hash,
-    // enforced by the type signature above
-    return keccak256(
-      abi.encodePacked("\x19Ethereum Signed Message:\n32", hash)
-    );
-  }
 }

contracts/cryptography/MerkleProof.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 /**
  * @title MerkleProof
@@ -6,37 +6,29 @@ pragma solidity ^0.4.24;
  * https://github.com/ameensol/merkle-tree-solidity/blob/master/src/MerkleProof.sol
  */
 library MerkleProof {
-  /**
-   * @dev Verifies a Merkle proof proving the existence of a leaf in a Merkle tree. Assumes that each pair of leaves
-   * and each pair of pre-images are sorted.
-   * @param proof Merkle proof containing sibling hashes on the branch from the leaf to the root of the Merkle tree
-   * @param root Merkle root
-   * @param leaf Leaf of Merkle tree
-   */
-  function verify(
-    bytes32[] proof,
-    bytes32 root,
-    bytes32 leaf
-  )
-    internal
-    pure
-    returns (bool)
-  {
-    bytes32 computedHash = leaf;
+    /**
+     * @dev Verifies a Merkle proof proving the existence of a leaf in a Merkle tree. Assumes that each pair of leaves
+     * and each pair of pre-images are sorted.
+     * @param proof Merkle proof containing sibling hashes on the branch from the leaf to the root of the Merkle tree
+     * @param root Merkle root
+     * @param leaf Leaf of Merkle tree
+     */
+    function verify(bytes32[] memory proof, bytes32 root, bytes32 leaf) internal pure returns (bool) {
+        bytes32 computedHash = leaf;
 
-    for (uint256 i = 0; i < proof.length; i++) {
-      bytes32 proofElement = proof[i];
+        for (uint256 i = 0; i < proof.length; i++) {
+            bytes32 proofElement = proof[i];
 
-      if (computedHash < proofElement) {
-        // Hash(current computed hash + current element of the proof)
-        computedHash = keccak256(abi.encodePacked(computedHash, proofElement));
-      } else {
-        // Hash(current element of the proof + current computed hash)
-        computedHash = keccak256(abi.encodePacked(proofElement, computedHash));
-      }
+            if (computedHash < proofElement) {
+                // Hash(current computed hash + current element of the proof)
+                computedHash = keccak256(abi.encodePacked(computedHash, proofElement));
+            } else {
+                // Hash(current element of the proof + current computed hash)
+                computedHash = keccak256(abi.encodePacked(proofElement, computedHash));
+            }
+        }
+
+        // Check if the computed hash (root) is equal to the provided root
+        return computedHash == root;
     }
-
-    // Check if the computed hash (root) is equal to the provided root
-    return computedHash == root;
-  }
 }

contracts/drafts/Counter.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 /**
  * @title Counter
@@ -13,16 +13,12 @@ pragma solidity ^0.4.24;
  * so it's not something you have to worry about.)
  */
 library Counter {
+    struct Counter {
+        uint256 current; // default: 0
+    }
 
-  struct Counter {
-    uint256 current; // default: 0
-  }
-
-  function next(Counter storage index)
-    internal
-    returns (uint256)
-  {
-    index.current += 1;
-    return index.current;
-  }
+    function next(Counter storage index) internal returns (uint256) {
+        index.current += 1;
+        return index.current;
+    }
 }

contracts/drafts/ERC1046/TokenMetadata.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../../token/ERC20/IERC20.sol";
 
@@ -6,22 +6,19 @@ import "../../token/ERC20/IERC20.sol";
  * @title ERC-1047 Token Metadata
  * @dev See https://eips.ethereum.org/EIPS/eip-1046
  * @dev tokenURI must respond with a URI that implements https://eips.ethereum.org/EIPS/eip-1047
- * @dev TODO - update https://github.com/OpenZeppelin/openzeppelin-solidity/blob/master/contracts/token/ERC721/IERC721.sol#L17 when 1046 is finalized
  */
 contract ERC20TokenMetadata is IERC20 {
-  function tokenURI() external view returns (string);
+    function tokenURI() external view returns (string memory);
 }
 
 contract ERC20WithMetadata is ERC20TokenMetadata {
-  string private _tokenURI;
+    string private _tokenURI;
 
-  constructor(string tokenURI)
-    public
-  {
-    _tokenURI = tokenURI;
-  }
+    constructor (string memory tokenURI) public {
+        _tokenURI = tokenURI;
+    }
 
-  function tokenURI() external view returns (string) {
-    return _tokenURI;
-  }
+    function tokenURI() external view returns (string memory) {
+        return _tokenURI;
+    }
 }

contracts/drafts/ERC20Migrator.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/IERC20.sol";
 import "../token/ERC20/ERC20Mintable.sol";
@@ -32,69 +32,69 @@ import "../math/Math.sol";
  * ```
  */
 contract ERC20Migrator {
-  using SafeERC20 for IERC20;
+    using SafeERC20 for IERC20;
 
-  /// Address of the old token contract
-  IERC20 private _legacyToken;
+    /// Address of the old token contract
+    IERC20 private _legacyToken;
 
-  /// Address of the new token contract
-  ERC20Mintable private _newToken;
+    /// Address of the new token contract
+    ERC20Mintable private _newToken;
 
-  /**
-   * @param legacyToken address of the old token contract
-   */
-  constructor(IERC20 legacyToken) public {
-    require(legacyToken != address(0));
-    _legacyToken = legacyToken;
-  }
+    /**
+     * @param legacyToken address of the old token contract
+     */
+    constructor (IERC20 legacyToken) public {
+        require(address(legacyToken) != address(0));
+        _legacyToken = legacyToken;
+    }
 
-  /**
-   * @dev Returns the legacy token that is being migrated.
-   */
-  function legacyToken() public view returns (IERC20) {
-    return _legacyToken;
-  }
+    /**
+     * @dev Returns the legacy token that is being migrated.
+     */
+    function legacyToken() public view returns (IERC20) {
+        return _legacyToken;
+    }
 
-  /**
-   * @dev Returns the new token to which we are migrating.
-   */
-  function newToken() public view returns (IERC20) {
-    return _newToken;
-  }
+    /**
+     * @dev Returns the new token to which we are migrating.
+     */
+    function newToken() public view returns (IERC20) {
+        return _newToken;
+    }
 
-  /**
-   * @dev Begins the migration by setting which is the new token that will be
-   * minted. This contract must be a minter for the new token.
-   * @param newToken the token that will be minted
-   */
-  function beginMigration(ERC20Mintable newToken) public {
-    require(_newToken == address(0));
-    require(newToken != address(0));
-    require(newToken.isMinter(this));
+    /**
+     * @dev Begins the migration by setting which is the new token that will be
+     * minted. This contract must be a minter for the new token.
+     * @param newToken the token that will be minted
+     */
+    function beginMigration(ERC20Mintable newToken) public {
+        require(address(_newToken) == address(0));
+        require(address(newToken) != address(0));
+        require(newToken.isMinter(address(this)));
 
-    _newToken = newToken;
-  }
+        _newToken = newToken;
+    }
 
-  /**
-   * @dev Transfers part of an account's balance in the old token to this
-   * contract, and mints the same amount of new tokens for that account.
-   * @param account whose tokens will be migrated
-   * @param amount amount of tokens to be migrated
-   */
-  function migrate(address account, uint256 amount) public {
-    _legacyToken.safeTransferFrom(account, this, amount);
-    _newToken.mint(account, amount);
-  }
+    /**
+     * @dev Transfers part of an account's balance in the old token to this
+     * contract, and mints the same amount of new tokens for that account.
+     * @param account whose tokens will be migrated
+     * @param amount amount of tokens to be migrated
+     */
+    function migrate(address account, uint256 amount) public {
+        _legacyToken.safeTransferFrom(account, address(this), amount);
+        _newToken.mint(account, amount);
+    }
 
-  /**
-   * @dev Transfers all of an account's allowed balance in the old token to
-   * this contract, and mints the same amount of new tokens for that account.
-   * @param account whose tokens will be migrated
-   */
-  function migrateAll(address account) public {
-    uint256 balance = _legacyToken.balanceOf(account);
-    uint256 allowance = _legacyToken.allowance(account, this);
-    uint256 amount = Math.min(balance, allowance);
-    migrate(account, amount);
-  }
+    /**
+     * @dev Transfers all of an account's allowed balance in the old token to
+     * this contract, and mints the same amount of new tokens for that account.
+     * @param account whose tokens will be migrated
+     */
+    function migrateAll(address account) public {
+        uint256 balance = _legacyToken.balanceOf(account);
+        uint256 allowance = _legacyToken.allowance(account, address(this));
+        uint256 amount = Math.min(balance, allowance);
+        migrate(account, amount);
+    }
 }

contracts/drafts/SignatureBouncer.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../access/roles/SignerRole.sol";
 import "../cryptography/ECDSA.sol";
@@ -35,112 +35,86 @@ import "../cryptography/ECDSA.sol";
  * See https://ethereum.stackexchange.com/a/50616 for more details.
  */
 contract SignatureBouncer is SignerRole {
-  using ECDSA for bytes32;
+    using ECDSA for bytes32;
 
-  // Function selectors are 4 bytes long, as documented in
-  // https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector
-  uint256 private constant _METHOD_ID_SIZE = 4;
-  // Signature size is 65 bytes (tightly packed v + r + s), but gets padded to 96 bytes
-  uint256 private constant _SIGNATURE_SIZE = 96;
+    // Function selectors are 4 bytes long, as documented in
+    // https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector
+    uint256 private constant _METHOD_ID_SIZE = 4;
+    // Signature size is 65 bytes (tightly packed v + r + s), but gets padded to 96 bytes
+    uint256 private constant _SIGNATURE_SIZE = 96;
 
-  constructor() internal {}
-
-  /**
-   * @dev requires that a valid signature of a signer was provided
-   */
-  modifier onlyValidSignature(bytes signature)
-  {
-    require(_isValidSignature(msg.sender, signature));
-    _;
-  }
-
-  /**
-   * @dev requires that a valid signature with a specifed method of a signer was provided
-   */
-  modifier onlyValidSignatureAndMethod(bytes signature)
-  {
-    require(_isValidSignatureAndMethod(msg.sender, signature));
-    _;
-  }
-
-  /**
-   * @dev requires that a valid signature with a specifed method and params of a signer was provided
-   */
-  modifier onlyValidSignatureAndData(bytes signature)
-  {
-    require(_isValidSignatureAndData(msg.sender, signature));
-    _;
-  }
-
-  /**
-   * @dev is the signature of `this + sender` from a signer?
-   * @return bool
-   */
-  function _isValidSignature(address account, bytes signature)
-    internal
-    view
-    returns (bool)
-  {
-    return _isValidDataHash(
-      keccak256(abi.encodePacked(address(this), account)),
-      signature
-    );
-  }
-
-  /**
-   * @dev is the signature of `this + sender + methodId` from a signer?
-   * @return bool
-   */
-  function _isValidSignatureAndMethod(address account, bytes signature)
-    internal
-    view
-    returns (bool)
-  {
-    bytes memory data = new bytes(_METHOD_ID_SIZE);
-    for (uint i = 0; i < data.length; i++) {
-      data[i] = msg.data[i];
+    constructor () internal {
+        // solhint-disable-previous-line no-empty-blocks
     }
-    return _isValidDataHash(
-      keccak256(abi.encodePacked(address(this), account, data)),
-      signature
-    );
-  }
 
-  /**
-    * @dev is the signature of `this + sender + methodId + params(s)` from a signer?
-    * @notice the signature parameter of the method being validated must be the "last" parameter
-    * @return bool
-    */
-  function _isValidSignatureAndData(address account, bytes signature)
-    internal
-    view
-    returns (bool)
-  {
-    require(msg.data.length > _SIGNATURE_SIZE);
-    bytes memory data = new bytes(msg.data.length - _SIGNATURE_SIZE);
-    for (uint i = 0; i < data.length; i++) {
-      data[i] = msg.data[i];
+    /**
+     * @dev requires that a valid signature of a signer was provided
+     */
+    modifier onlyValidSignature(bytes memory signature) {
+        require(_isValidSignature(msg.sender, signature));
+        _;
     }
-    return _isValidDataHash(
-      keccak256(abi.encodePacked(address(this), account, data)),
-      signature
-    );
-  }
 
-  /**
-   * @dev internal function to convert a hash to an eth signed message
-   * and then recover the signature and check it against the signer role
-   * @return bool
-   */
-  function _isValidDataHash(bytes32 hash, bytes signature)
-    internal
-    view
-    returns (bool)
-  {
-    address signer = hash
-      .toEthSignedMessageHash()
-      .recover(signature);
+    /**
+     * @dev requires that a valid signature with a specifed method of a signer was provided
+     */
+    modifier onlyValidSignatureAndMethod(bytes memory signature) {
+        require(_isValidSignatureAndMethod(msg.sender, signature));
+        _;
+    }
 
-    return signer != address(0) && isSigner(signer);
-  }
+    /**
+     * @dev requires that a valid signature with a specifed method and params of a signer was provided
+     */
+    modifier onlyValidSignatureAndData(bytes memory signature) {
+        require(_isValidSignatureAndData(msg.sender, signature));
+        _;
+    }
+
+    /**
+     * @dev is the signature of `this + sender` from a signer?
+     * @return bool
+     */
+    function _isValidSignature(address account, bytes memory signature) internal view returns (bool) {
+        return _isValidDataHash(keccak256(abi.encodePacked(address(this), account)), signature);
+    }
+
+    /**
+     * @dev is the signature of `this + sender + methodId` from a signer?
+     * @return bool
+     */
+    function _isValidSignatureAndMethod(address account, bytes memory signature) internal view returns (bool) {
+        bytes memory data = new bytes(_METHOD_ID_SIZE);
+        for (uint i = 0; i < data.length; i++) {
+            data[i] = msg.data[i];
+        }
+        return _isValidDataHash(keccak256(abi.encodePacked(address(this), account, data)), signature);
+    }
+
+    /**
+        * @dev is the signature of `this + sender + methodId + params(s)` from a signer?
+        * @notice the signature parameter of the method being validated must be the "last" parameter
+        * @return bool
+        */
+    function _isValidSignatureAndData(address account, bytes memory signature) internal view returns (bool) {
+        require(msg.data.length > _SIGNATURE_SIZE);
+
+        bytes memory data = new bytes(msg.data.length - _SIGNATURE_SIZE);
+        for (uint i = 0; i < data.length; i++) {
+            data[i] = msg.data[i];
+        }
+
+        return _isValidDataHash(keccak256(abi.encodePacked(address(this), account, data)), signature);
+    }
+
+    /**
+     * @dev internal function to convert a hash to an eth signed message
+     * and then recover the signature and check it against the signer role
+     * @return bool
+     */
+    function _isValidDataHash(bytes32 hash, bytes memory signature) internal view returns (bool) {
+        address signer = hash.toEthSignedMessageHash().recover(signature);
+
+        return signer != address(0) && isSigner(signer);
+    }
 }

contracts/drafts/SignedSafeMath.sol

@@ -0,0 +1,60 @@
+pragma solidity ^0.5.0;
+
+/**
+ * @title SignedSafeMath
+ * @dev Signed math operations with safety checks that revert on error
+ */
+library SignedSafeMath {
+    int256 constant private INT256_MIN = -2**255;
+
+    /**
+    * @dev Multiplies two signed integers, reverts on overflow.
+    */
+    function mul(int256 a, int256 b) internal pure returns (int256) {
+        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
+        // benefit is lost if 'b' is also tested.
+        // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
+        if (a == 0) {
+            return 0;
+        }
+
+        require(!(a == -1 && b == INT256_MIN)); // This is the only case of overflow not detected by the check below
+
+        int256 c = a * b;
+        require(c / a == b);
+
+        return c;
+    }
+
+    /**
+    * @dev Integer division of two signed integers truncating the quotient, reverts on division by zero.
+    */
+    function div(int256 a, int256 b) internal pure returns (int256) {
+        require(b != 0); // Solidity only automatically asserts when dividing by 0
+        require(!(b == -1 && a == INT256_MIN)); // This is the only case of overflow
+
+        int256 c = a / b;
+
+        return c;
+    }
+
+    /**
+    * @dev Subtracts two signed integers, reverts on overflow.
+    */
+    function sub(int256 a, int256 b) internal pure returns (int256) {
+        int256 c = a - b;
+        require((b >= 0 && c <= a) || (b < 0 && c > a));
+
+        return c;
+    }
+
+    /**
+    * @dev Adds two signed integers, reverts on overflow.
+    */
+    function add(int256 a, int256 b) internal pure returns (int256) {
+        int256 c = a + b;
+        require((b >= 0 && c >= a) || (b < 0 && c < a));
+
+        return c;
+    }
+}

contracts/drafts/TokenVesting.sol

@@ -1,6 +1,4 @@
-/* solium-disable security/no-block-members */
-
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/SafeERC20.sol";
 import "../ownership/Ownable.sol";
@@ -13,163 +11,162 @@ import "../math/SafeMath.sol";
  * owner.
  */
 contract TokenVesting is Ownable {
-  using SafeMath for uint256;
-  using SafeERC20 for IERC20;
+    // The vesting schedule is time-based (i.e. using block timestamps as opposed to e.g. block numbers), and is
+    // therefore sensitive to timestamp manipulation (which is something miners can do, to a certain degree). Therefore,
+    // it is recommended to avoid using short time durations (less than a minute). Typical vesting schemes, with a cliff
+    // period of a year and a duration of four years, are safe to use.
+    // solhint-disable not-rely-on-time
 
-  event TokensReleased(address token, uint256 amount);
-  event TokenVestingRevoked(address token);
+    using SafeMath for uint256;
+    using SafeERC20 for IERC20;
 
-  // beneficiary of tokens after they are released
-  address private _beneficiary;
+    event TokensReleased(address token, uint256 amount);
+    event TokenVestingRevoked(address token);
 
-  uint256 private _cliff;
-  uint256 private _start;
-  uint256 private _duration;
+    // beneficiary of tokens after they are released
+    address private _beneficiary;
 
-  bool private _revocable;
+    // Durations and timestamps are expressed in UNIX time, the same units as block.timestamp.
+    uint256 private _cliff;
+    uint256 private _start;
+    uint256 private _duration;
 
-  mapping (address => uint256) private _released;
-  mapping (address => bool) private _revoked;
+    bool private _revocable;
 
-  /**
-   * @dev Creates a vesting contract that vests its balance of any ERC20 token to the
-   * beneficiary, gradually in a linear fashion until start + duration. By then all
-   * of the balance will have vested.
-   * @param beneficiary address of the beneficiary to whom vested tokens are transferred
-   * @param cliffDuration duration in seconds of the cliff in which tokens will begin to vest
-   * @param start the time (as Unix time) at which point vesting starts
-   * @param duration duration in seconds of the period in which the tokens will vest
-   * @param revocable whether the vesting is revocable or not
-   */
-  constructor(
-    address beneficiary,
-    uint256 start,
-    uint256 cliffDuration,
-    uint256 duration,
-    bool revocable
-  )
-    public
-  {
-    require(beneficiary != address(0));
-    require(cliffDuration <= duration);
-    require(duration > 0);
-    require(start.add(duration) > block.timestamp);
+    mapping (address => uint256) private _released;
+    mapping (address => bool) private _revoked;
 
-    _beneficiary = beneficiary;
-    _revocable = revocable;
-    _duration = duration;
-    _cliff = start.add(cliffDuration);
-    _start = start;
-  }
+    /**
+     * @dev Creates a vesting contract that vests its balance of any ERC20 token to the
+     * beneficiary, gradually in a linear fashion until start + duration. By then all
+     * of the balance will have vested.
+     * @param beneficiary address of the beneficiary to whom vested tokens are transferred
+     * @param cliffDuration duration in seconds of the cliff in which tokens will begin to vest
+     * @param start the time (as Unix time) at which point vesting starts
+     * @param duration duration in seconds of the period in which the tokens will vest
+     * @param revocable whether the vesting is revocable or not
+     */
+    constructor (address beneficiary, uint256 start, uint256 cliffDuration, uint256 duration, bool revocable) public {
+        require(beneficiary != address(0));
+        require(cliffDuration <= duration);
+        require(duration > 0);
+        require(start.add(duration) > block.timestamp);
 
-  /**
-   * @return the beneficiary of the tokens.
-   */
-  function beneficiary() public view returns(address) {
-    return _beneficiary;
-  }
-
-  /**
-   * @return the cliff time of the token vesting.
-   */
-  function cliff() public view returns(uint256) {
-    return _cliff;
-  }
-
-  /**
-   * @return the start time of the token vesting.
-   */
-  function start() public view returns(uint256) {
-    return _start;
-  }
-
-  /**
-   * @return the duration of the token vesting.
-   */
-  function duration() public view returns(uint256) {
-    return _duration;
-  }
-
-  /**
-   * @return true if the vesting is revocable.
-   */
-  function revocable() public view returns(bool) {
-    return _revocable;
-  }
-
-  /**
-   * @return the amount of the token released.
-   */
-  function released(address token) public view returns(uint256) {
-    return _released[token];
-  }
-
-  /**
-   * @return true if the token is revoked.
-   */
-  function revoked(address token) public view returns(bool) {
-    return _revoked[token];
-  }
-
-  /**
-   * @notice Transfers vested tokens to beneficiary.
-   * @param token ERC20 token which is being vested
-   */
-  function release(IERC20 token) public {
-    uint256 unreleased = _releasableAmount(token);
-
-    require(unreleased > 0);
-
-    _released[token] = _released[token].add(unreleased);
-
-    token.safeTransfer(_beneficiary, unreleased);
-
-    emit TokensReleased(token, unreleased);
-  }
-
-  /**
-   * @notice Allows the owner to revoke the vesting. Tokens already vested
-   * remain in the contract, the rest are returned to the owner.
-   * @param token ERC20 token which is being vested
-   */
-  function revoke(IERC20 token) public onlyOwner {
-    require(_revocable);
-    require(!_revoked[token]);
-
-    uint256 balance = token.balanceOf(address(this));
-
-    uint256 unreleased = _releasableAmount(token);
-    uint256 refund = balance.sub(unreleased);
-
-    _revoked[token] = true;
-
-    token.safeTransfer(owner(), refund);
-
-    emit TokenVestingRevoked(token);
-  }
-
-  /**
-   * @dev Calculates the amount that has already vested but hasn't been released yet.
-   * @param token ERC20 token which is being vested
-   */
-  function _releasableAmount(IERC20 token) private view returns (uint256) {
-    return _vestedAmount(token).sub(_released[token]);
-  }
-
-  /**
-   * @dev Calculates the amount that has already vested.
-   * @param token ERC20 token which is being vested
-   */
-  function _vestedAmount(IERC20 token) private view returns (uint256) {
-    uint256 currentBalance = token.balanceOf(this);
-    uint256 totalBalance = currentBalance.add(_released[token]);
-
-    if (block.timestamp < _cliff) {
-      return 0;
-    } else if (block.timestamp >= _start.add(_duration) || _revoked[token]) {
-      return totalBalance;
-    } else {
-      return totalBalance.mul(block.timestamp.sub(_start)).div(_duration);
+        _beneficiary = beneficiary;
+        _revocable = revocable;
+        _duration = duration;
+        _cliff = start.add(cliffDuration);
+        _start = start;
+    }
+
+    /**
+     * @return the beneficiary of the tokens.
+     */
+    function beneficiary() public view returns (address) {
+        return _beneficiary;
+    }
+
+    /**
+     * @return the cliff time of the token vesting.
+     */
+    function cliff() public view returns (uint256) {
+        return _cliff;
+    }
+
+    /**
+     * @return the start time of the token vesting.
+     */
+    function start() public view returns (uint256) {
+        return _start;
+    }
+
+    /**
+     * @return the duration of the token vesting.
+     */
+    function duration() public view returns (uint256) {
+        return _duration;
+    }
+
+    /**
+     * @return true if the vesting is revocable.
+     */
+    function revocable() public view returns (bool) {
+        return _revocable;
+    }
+
+    /**
+     * @return the amount of the token released.
+     */
+    function released(address token) public view returns (uint256) {
+        return _released[token];
+    }
+
+    /**
+     * @return true if the token is revoked.
+     */
+    function revoked(address token) public view returns (bool) {
+        return _revoked[token];
+    }
+
+    /**
+     * @notice Transfers vested tokens to beneficiary.
+     * @param token ERC20 token which is being vested
+     */
+    function release(IERC20 token) public {
+        uint256 unreleased = _releasableAmount(token);
+
+        require(unreleased > 0);
+
+        _released[address(token)] = _released[address(token)].add(unreleased);
+
+        token.safeTransfer(_beneficiary, unreleased);
+
+        emit TokensReleased(address(token), unreleased);
+    }
+
+    /**
+     * @notice Allows the owner to revoke the vesting. Tokens already vested
+     * remain in the contract, the rest are returned to the owner.
+     * @param token ERC20 token which is being vested
+     */
+    function revoke(IERC20 token) public onlyOwner {
+        require(_revocable);
+        require(!_revoked[address(token)]);
+
+        uint256 balance = token.balanceOf(address(this));
+
+        uint256 unreleased = _releasableAmount(token);
+        uint256 refund = balance.sub(unreleased);
+
+        _revoked[address(token)] = true;
+
+        token.safeTransfer(owner(), refund);
+
+        emit TokenVestingRevoked(address(token));
+    }
+
+    /**
+     * @dev Calculates the amount that has already vested but hasn't been released yet.
+     * @param token ERC20 token which is being vested
+     */
+    function _releasableAmount(IERC20 token) private view returns (uint256) {
+        return _vestedAmount(token).sub(_released[address(token)]);
+    }
+
+    /**
+     * @dev Calculates the amount that has already vested.
+     * @param token ERC20 token which is being vested
+     */
+    function _vestedAmount(IERC20 token) private view returns (uint256) {
+        uint256 currentBalance = token.balanceOf(address(this));
+        uint256 totalBalance = currentBalance.add(_released[address(token)]);
+
+        if (block.timestamp < _cliff) {
+            return 0;
+        } else if (block.timestamp >= _start.add(_duration) || _revoked[address(token)]) {
+            return totalBalance;
+        } else {
+            return totalBalance.mul(block.timestamp.sub(_start)).div(_duration);
+        }
     }
-  }
 }

contracts/examples/SampleCrowdsale.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../crowdsale/validation/CappedCrowdsale.sol";
 import "../crowdsale/distribution/RefundableCrowdsale.sol";
@@ -12,7 +12,9 @@ import "../token/ERC20/ERC20Detailed.sol";
  * It is meant to be used in a crowdsale contract.
  */
 contract SampleCrowdsaleToken is ERC20Mintable, ERC20Detailed {
-  constructor() public ERC20Detailed("Sample Crowdsale Token", "SCT", 18) {}
+    constructor () public ERC20Detailed("Sample Crowdsale Token", "SCT", 18) {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 }
 
 /**
@@ -28,30 +30,24 @@ contract SampleCrowdsaleToken is ERC20Mintable, ERC20Detailed {
  * After adding multiple features it's good practice to run integration tests
  * to ensure that subcontracts works together as intended.
  */
-// XXX There doesn't seem to be a way to split this line that keeps solium
-// happy. See:
-// https://github.com/duaraghav8/Solium/issues/205
-// --elopio - 2018-05-10
-// solium-disable-next-line max-len
 contract SampleCrowdsale is CappedCrowdsale, RefundableCrowdsale, MintedCrowdsale {
-
-  constructor(
-    uint256 openingTime,
-    uint256 closingTime,
-    uint256 rate,
-    address wallet,
-    uint256 cap,
-    ERC20Mintable token,
-    uint256 goal
-  )
-    public
-    Crowdsale(rate, wallet, token)
-    CappedCrowdsale(cap)
-    TimedCrowdsale(openingTime, closingTime)
-    RefundableCrowdsale(goal)
-  {
-    //As goal needs to be met for a successful crowdsale
-    //the value needs to less or equal than a cap which is limit for accepted funds
-    require(goal <= cap);
-  }
+    constructor (
+        uint256 openingTime,
+        uint256 closingTime,
+        uint256 rate,
+        address payable wallet,
+        uint256 cap,
+        ERC20Mintable token,
+        uint256 goal
+    )
+        public
+        Crowdsale(rate, wallet, token)
+        CappedCrowdsale(cap)
+        TimedCrowdsale(openingTime, closingTime)
+        RefundableCrowdsale(goal)
+    {
+        //As goal needs to be met for a successful crowdsale
+        //the value needs to less or equal than a cap which is limit for accepted funds
+        require(goal <= cap);
+    }
 }

contracts/examples/SimpleToken.sol

@@ -1,6 +1,7 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/ERC20.sol";
+import "../token/ERC20/ERC20Detailed.sol";
 
 /**
  * @title SimpleToken
@@ -8,19 +9,14 @@ import "../token/ERC20/ERC20.sol";
  * Note they can later distribute these tokens as they wish using `transfer` and other
  * `ERC20` functions.
  */
-contract SimpleToken is ERC20 {
-
-  string public constant name = "SimpleToken";
-  string public constant symbol = "SIM";
-  uint8 public constant decimals = 18;
-
-  uint256 public constant INITIAL_SUPPLY = 10000 * (10 ** uint256(decimals));
-
-  /**
-   * @dev Constructor that gives msg.sender all of existing tokens.
-   */
-  constructor() public {
-    _mint(msg.sender, INITIAL_SUPPLY);
-  }
+contract SimpleToken is ERC20, ERC20Detailed {
+    uint8 public constant DECIMALS = 18;
+    uint256 public constant INITIAL_SUPPLY = 10000 * (10 ** uint256(DECIMALS));
 
+    /**
+     * @dev Constructor that gives msg.sender all of existing tokens.
+     */
+    constructor () public ERC20Detailed("SimpleToken", "SIM", DECIMALS) {
+        _mint(msg.sender, INITIAL_SUPPLY);
+    }
 }

contracts/introspection/ERC165.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "./IERC165.sol";
 
@@ -8,46 +8,37 @@ import "./IERC165.sol";
  * @dev Implements ERC165 using a lookup table.
  */
 contract ERC165 is IERC165 {
+    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;
+    /**
+     * 0x01ffc9a7 ===
+     *     bytes4(keccak256('supportsInterface(bytes4)'))
+     */
 
-  bytes4 private constant _InterfaceId_ERC165 = 0x01ffc9a7;
-  /**
-   * 0x01ffc9a7 ===
-   *   bytes4(keccak256('supportsInterface(bytes4)'))
-   */
+    /**
+     * @dev a mapping of interface id to whether or not it's supported
+     */
+    mapping(bytes4 => bool) private _supportedInterfaces;
 
-  /**
-   * @dev a mapping of interface id to whether or not it's supported
-   */
-  mapping(bytes4 => bool) private _supportedInterfaces;
+    /**
+     * @dev A contract implementing SupportsInterfaceWithLookup
+     * implement ERC165 itself
+     */
+    constructor () internal {
+        _registerInterface(_INTERFACE_ID_ERC165);
+    }
 
-  /**
-   * @dev A contract implementing SupportsInterfaceWithLookup
-   * implement ERC165 itself
-   */
-  constructor()
-    internal
-  {
-    _registerInterface(_InterfaceId_ERC165);
-  }
+    /**
+     * @dev implement supportsInterface(bytes4) using a lookup table
+     */
+    function supportsInterface(bytes4 interfaceId) external view returns (bool) {
+        return _supportedInterfaces[interfaceId];
+    }
 
-  /**
-   * @dev implement supportsInterface(bytes4) using a lookup table
-   */
-  function supportsInterface(bytes4 interfaceId)
-    external
-    view
-    returns (bool)
-  {
-    return _supportedInterfaces[interfaceId];
-  }
-
-  /**
-   * @dev internal method for registering an interface
-   */
-  function _registerInterface(bytes4 interfaceId)
-    internal
-  {
-    require(interfaceId != 0xffffffff);
-    _supportedInterfaces[interfaceId] = true;
-  }
+    /**
+     * @dev internal method for registering an interface
+     */
+    function _registerInterface(bytes4 interfaceId) internal {
+        require(interfaceId != 0xffffffff);
+        _supportedInterfaces[interfaceId] = true;
+    }
 }

contracts/introspection/ERC165Checker.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 /**
  * @title ERC165Checker
@@ -6,141 +6,118 @@ pragma solidity ^0.4.24;
  * https://github.com/ethereum/EIPs/blob/master/EIPS/eip-165.md
  */
 library ERC165Checker {
-  // As per the EIP-165 spec, no interface should ever match 0xffffffff
-  bytes4 private constant _InterfaceId_Invalid = 0xffffffff;
+    // As per the EIP-165 spec, no interface should ever match 0xffffffff
+    bytes4 private constant _INTERFACE_ID_INVALID = 0xffffffff;
 
-  bytes4 private constant _InterfaceId_ERC165 = 0x01ffc9a7;
-  /**
-   * 0x01ffc9a7 ===
-   *   bytes4(keccak256('supportsInterface(bytes4)'))
-   */
+    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;
+    /**
+     * 0x01ffc9a7 ===
+     *     bytes4(keccak256('supportsInterface(bytes4)'))
+     */
 
-  /**
-   * @notice Query if a contract supports ERC165
-   * @param account The address of the contract to query for support of ERC165
-   * @return true if the contract at account implements ERC165
-   */
-  function _supportsERC165(address account)
-    internal
-    view
-    returns (bool)
-  {
-    // Any contract that implements ERC165 must explicitly indicate support of
-    // InterfaceId_ERC165 and explicitly indicate non-support of InterfaceId_Invalid
-    return _supportsERC165Interface(account, _InterfaceId_ERC165) &&
-      !_supportsERC165Interface(account, _InterfaceId_Invalid);
-  }
-
-  /**
-   * @notice Query if a contract implements an interface, also checks support of ERC165
-   * @param account The address of the contract to query for support of an interface
-   * @param interfaceId The interface identifier, as specified in ERC-165
-   * @return true if the contract at account indicates support of the interface with
-   * identifier interfaceId, false otherwise
-   * @dev Interface identification is specified in ERC-165.
-   */
-  function _supportsInterface(address account, bytes4 interfaceId)
-    internal
-    view
-    returns (bool)
-  {
-    // query support of both ERC165 as per the spec and support of _interfaceId
-    return _supportsERC165(account) &&
-      _supportsERC165Interface(account, interfaceId);
-  }
-
-  /**
-   * @notice Query if a contract implements interfaces, also checks support of ERC165
-   * @param account The address of the contract to query for support of an interface
-   * @param interfaceIds A list of interface identifiers, as specified in ERC-165
-   * @return true if the contract at account indicates support all interfaces in the
-   * interfaceIds list, false otherwise
-   * @dev Interface identification is specified in ERC-165.
-   */
-  function _supportsAllInterfaces(address account, bytes4[] interfaceIds)
-    internal
-    view
-    returns (bool)
-  {
-    // query support of ERC165 itself
-    if (!_supportsERC165(account)) {
-      return false;
+    /**
+     * @notice Query if a contract supports ERC165
+     * @param account The address of the contract to query for support of ERC165
+     * @return true if the contract at account implements ERC165
+     */
+    function _supportsERC165(address account) internal view returns (bool) {
+        // Any contract that implements ERC165 must explicitly indicate support of
+        // InterfaceId_ERC165 and explicitly indicate non-support of InterfaceId_Invalid
+        return _supportsERC165Interface(account, _INTERFACE_ID_ERC165) &&
+            !_supportsERC165Interface(account, _INTERFACE_ID_INVALID);
     }
 
-    // query support of each interface in _interfaceIds
-    for (uint256 i = 0; i < interfaceIds.length; i++) {
-      if (!_supportsERC165Interface(account, interfaceIds[i])) {
-        return false;
-      }
+    /**
+     * @notice Query if a contract implements an interface, also checks support of ERC165
+     * @param account The address of the contract to query for support of an interface
+     * @param interfaceId The interface identifier, as specified in ERC-165
+     * @return true if the contract at account indicates support of the interface with
+     * identifier interfaceId, false otherwise
+     * @dev Interface identification is specified in ERC-165.
+     */
+    function _supportsInterface(address account, bytes4 interfaceId) internal view returns (bool) {
+        // query support of both ERC165 as per the spec and support of _interfaceId
+        return _supportsERC165(account) &&
+            _supportsERC165Interface(account, interfaceId);
     }
 
-    // all interfaces supported
-    return true;
-  }
+    /**
+     * @notice Query if a contract implements interfaces, also checks support of ERC165
+     * @param account The address of the contract to query for support of an interface
+     * @param interfaceIds A list of interface identifiers, as specified in ERC-165
+     * @return true if the contract at account indicates support all interfaces in the
+     * interfaceIds list, false otherwise
+     * @dev Interface identification is specified in ERC-165.
+     */
+    function _supportsAllInterfaces(address account, bytes4[] memory interfaceIds) internal view returns (bool) {
+        // query support of ERC165 itself
+        if (!_supportsERC165(account)) {
+            return false;
+        }
 
-  /**
-   * @notice Query if a contract implements an interface, does not check ERC165 support
-   * @param account The address of the contract to query for support of an interface
-   * @param interfaceId The interface identifier, as specified in ERC-165
-   * @return true if the contract at account indicates support of the interface with
-   * identifier interfaceId, false otherwise
-   * @dev Assumes that account contains a contract that supports ERC165, otherwise
-   * the behavior of this method is undefined. This precondition can be checked
-   * with the `supportsERC165` method in this library.
-   * Interface identification is specified in ERC-165.
-   */
-  function _supportsERC165Interface(address account, bytes4 interfaceId)
-    private
-    view
-    returns (bool)
-  {
-    // success determines whether the staticcall succeeded and result determines
-    // whether the contract at account indicates support of _interfaceId
-    (bool success, bool result) = _callERC165SupportsInterface(
-      account, interfaceId);
+        // query support of each interface in _interfaceIds
+        for (uint256 i = 0; i < interfaceIds.length; i++) {
+            if (!_supportsERC165Interface(account, interfaceIds[i])) {
+                return false;
+            }
+        }
 
-    return (success && result);
-  }
-
-  /**
-   * @notice Calls the function with selector 0x01ffc9a7 (ERC165) and suppresses throw
-   * @param account The address of the contract to query for support of an interface
-   * @param interfaceId The interface identifier, as specified in ERC-165
-   * @return success true if the STATICCALL succeeded, false otherwise
-   * @return result true if the STATICCALL succeeded and the contract at account
-   * indicates support of the interface with identifier interfaceId, false otherwise
-   */
-  function _callERC165SupportsInterface(
-    address account,
-    bytes4 interfaceId
-  )
-    private
-    view
-    returns (bool success, bool result)
-  {
-    bytes memory encodedParams = abi.encodeWithSelector(
-      _InterfaceId_ERC165,
-      interfaceId
-    );
-
-    // solium-disable-next-line security/no-inline-assembly
-    assembly {
-      let encodedParams_data := add(0x20, encodedParams)
-      let encodedParams_size := mload(encodedParams)
-
-      let output := mload(0x40)  // Find empty storage location using "free memory pointer"
-      mstore(output, 0x0)
-
-      success := staticcall(
-        30000,                 // 30k gas
-        account,              // To addr
-        encodedParams_data,
-        encodedParams_size,
-        output,
-        0x20                   // Outputs are 32 bytes long
-      )
-
-      result := mload(output)  // Load the result
+        // all interfaces supported
+        return true;
+    }
+
+    /**
+     * @notice Query if a contract implements an interface, does not check ERC165 support
+     * @param account The address of the contract to query for support of an interface
+     * @param interfaceId The interface identifier, as specified in ERC-165
+     * @return true if the contract at account indicates support of the interface with
+     * identifier interfaceId, false otherwise
+     * @dev Assumes that account contains a contract that supports ERC165, otherwise
+     * the behavior of this method is undefined. This precondition can be checked
+     * with the `supportsERC165` method in this library.
+     * Interface identification is specified in ERC-165.
+     */
+    function _supportsERC165Interface(address account, bytes4 interfaceId) private view returns (bool) {
+        // success determines whether the staticcall succeeded and result determines
+        // whether the contract at account indicates support of _interfaceId
+        (bool success, bool result) = _callERC165SupportsInterface(account, interfaceId);
+
+        return (success && result);
+    }
+
+    /**
+     * @notice Calls the function with selector 0x01ffc9a7 (ERC165) and suppresses throw
+     * @param account The address of the contract to query for support of an interface
+     * @param interfaceId The interface identifier, as specified in ERC-165
+     * @return success true if the STATICCALL succeeded, false otherwise
+     * @return result true if the STATICCALL succeeded and the contract at account
+     * indicates support of the interface with identifier interfaceId, false otherwise
+     */
+    function _callERC165SupportsInterface(address account, bytes4 interfaceId)
+        private
+        view
+        returns (bool success, bool result)
+    {
+        bytes memory encodedParams = abi.encodeWithSelector(_INTERFACE_ID_ERC165, interfaceId);
+
+        // solhint-disable-next-line no-inline-assembly
+        assembly {
+            let encodedParams_data := add(0x20, encodedParams)
+            let encodedParams_size := mload(encodedParams)
+
+            let output := mload(0x40)    // Find empty storage location using "free memory pointer"
+            mstore(output, 0x0)
+
+            success := staticcall(
+                30000,                                 // 30k gas
+                account,                            // To addr
+                encodedParams_data,
+                encodedParams_size,
+                output,
+                0x20                                     // Outputs are 32 bytes long
+            )
+
+            result := mload(output)    // Load the result
+        }
     }
-  }
 }

contracts/introspection/IERC165.sol

@@ -1,19 +1,15 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 /**
  * @title IERC165
  * @dev https://github.com/ethereum/EIPs/blob/master/EIPS/eip-165.md
  */
 interface IERC165 {
-
-  /**
-   * @notice Query if a contract implements an interface
-   * @param interfaceId The interface identifier, as specified in ERC-165
-   * @dev Interface identification is specified in ERC-165. This function
-   * uses less than 30,000 gas.
-   */
-  function supportsInterface(bytes4 interfaceId)
-    external
-    view
-    returns (bool);
+    /**
+     * @notice Query if a contract implements an interface
+     * @param interfaceId The interface identifier, as specified in ERC-165
+     * @dev Interface identification is specified in ERC-165. This function
+     * uses less than 30,000 gas.
+     */
+    function supportsInterface(bytes4 interfaceId) external view returns (bool);
 }

contracts/lifecycle/Pausable.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../access/roles/PauserRole.sol";
 
@@ -7,51 +7,51 @@ import "../access/roles/PauserRole.sol";
  * @dev Base contract which allows children to implement an emergency stop mechanism.
  */
 contract Pausable is PauserRole {
-  event Paused(address account);
-  event Unpaused(address account);
+    event Paused(address account);
+    event Unpaused(address account);
 
-  bool private _paused;
+    bool private _paused;
 
-  constructor() internal {
-    _paused = false;
-  }
+    constructor () internal {
+        _paused = false;
+    }
 
-  /**
-   * @return true if the contract is paused, false otherwise.
-   */
-  function paused() public view returns(bool) {
-    return _paused;
-  }
+    /**
+     * @return true if the contract is paused, false otherwise.
+     */
+    function paused() public view returns (bool) {
+        return _paused;
+    }
 
-  /**
-   * @dev Modifier to make a function callable only when the contract is not paused.
-   */
-  modifier whenNotPaused() {
-    require(!_paused);
-    _;
-  }
+    /**
+     * @dev Modifier to make a function callable only when the contract is not paused.
+     */
+    modifier whenNotPaused() {
+        require(!_paused);
+        _;
+    }
 
-  /**
-   * @dev Modifier to make a function callable only when the contract is paused.
-   */
-  modifier whenPaused() {
-    require(_paused);
-    _;
-  }
+    /**
+     * @dev Modifier to make a function callable only when the contract is paused.
+     */
+    modifier whenPaused() {
+        require(_paused);
+        _;
+    }
 
-  /**
-   * @dev called by the owner to pause, triggers stopped state
-   */
-  function pause() public onlyPauser whenNotPaused {
-    _paused = true;
-    emit Paused(msg.sender);
-  }
+    /**
+     * @dev called by the owner to pause, triggers stopped state
+     */
+    function pause() public onlyPauser whenNotPaused {
+        _paused = true;
+        emit Paused(msg.sender);
+    }
 
-  /**
-   * @dev called by the owner to unpause, returns to normal state
-   */
-  function unpause() public onlyPauser whenPaused {
-    _paused = false;
-    emit Unpaused(msg.sender);
-  }
+    /**
+     * @dev called by the owner to unpause, returns to normal state
+     */
+    function unpause() public onlyPauser whenPaused {
+        _paused = false;
+        emit Unpaused(msg.sender);
+    }
 }

contracts/math/Math.sol

@@ -1,31 +1,31 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 /**
  * @title Math
  * @dev Assorted math operations
  */
 library Math {
-  /**
-  * @dev Returns the largest of two numbers.
-  */
-  function max(uint256 a, uint256 b) internal pure returns (uint256) {
-    return a >= b ? a : b;
-  }
+    /**
+    * @dev Returns the largest of two numbers.
+    */
+    function max(uint256 a, uint256 b) internal pure returns (uint256) {
+        return a >= b ? a : b;
+    }
 
-  /**
-  * @dev Returns the smallest of two numbers.
-  */
-  function min(uint256 a, uint256 b) internal pure returns (uint256) {
-    return a < b ? a : b;
-  }
+    /**
+    * @dev Returns the smallest of two numbers.
+    */
+    function min(uint256 a, uint256 b) internal pure returns (uint256) {
+        return a < b ? a : b;
+    }
 
-  /**
-  * @dev Calculates the average of two numbers. Since these are integers,
-  * averages of an even and odd number cannot be represented, and will be
-  * rounded down.
-  */
-  function average(uint256 a, uint256 b) internal pure returns (uint256) {
-    // (a + b) / 2 can overflow, so we distribute
-    return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);
-  }
+    /**
+    * @dev Calculates the average of two numbers. Since these are integers,
+    * averages of an even and odd number cannot be represented, and will be
+    * rounded down.
+    */
+    function average(uint256 a, uint256 b) internal pure returns (uint256) {
+        // (a + b) / 2 can overflow, so we distribute
+        return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);
+    }
 }

contracts/math/SafeMath.sol

@@ -1,65 +1,65 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 /**
  * @title SafeMath
- * @dev Math operations with safety checks that revert on error
+ * @dev Unsigned math operations with safety checks that revert on error
  */
 library SafeMath {
+    /**
+    * @dev Multiplies two unsigned integers, reverts on overflow.
+    */
+    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
+        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
+        // benefit is lost if 'b' is also tested.
+        // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
+        if (a == 0) {
+            return 0;
+        }
 
-  /**
-  * @dev Multiplies two numbers, reverts on overflow.
-  */
-  function mul(uint256 a, uint256 b) internal pure returns (uint256) {
-    // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
-    // benefit is lost if 'b' is also tested.
-    // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
-    if (a == 0) {
-      return 0;
+        uint256 c = a * b;
+        require(c / a == b);
+
+        return c;
     }
 
-    uint256 c = a * b;
-    require(c / a == b);
+    /**
+    * @dev Integer division of two unsigned integers truncating the quotient, reverts on division by zero.
+    */
+    function div(uint256 a, uint256 b) internal pure returns (uint256) {
+        // Solidity only automatically asserts when dividing by 0
+        require(b > 0);
+        uint256 c = a / b;
+        // assert(a == b * c + a % b); // There is no case in which this doesn't hold
 
-    return c;
-  }
+        return c;
+    }
 
-  /**
-  * @dev Integer division of two numbers truncating the quotient, reverts on division by zero.
-  */
-  function div(uint256 a, uint256 b) internal pure returns (uint256) {
-    require(b > 0); // Solidity only automatically asserts when dividing by 0
-    uint256 c = a / b;
-    // assert(a == b * c + a % b); // There is no case in which this doesn't hold
+    /**
+    * @dev Subtracts two unsigned integers, reverts on overflow (i.e. if subtrahend is greater than minuend).
+    */
+    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
+        require(b <= a);
+        uint256 c = a - b;
 
-    return c;
-  }
+        return c;
+    }
 
-  /**
-  * @dev Subtracts two numbers, reverts on overflow (i.e. if subtrahend is greater than minuend).
-  */
-  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
-    require(b <= a);
-    uint256 c = a - b;
+    /**
+    * @dev Adds two unsigned integers, reverts on overflow.
+    */
+    function add(uint256 a, uint256 b) internal pure returns (uint256) {
+        uint256 c = a + b;
+        require(c >= a);
 
-    return c;
-  }
+        return c;
+    }
 
-  /**
-  * @dev Adds two numbers, reverts on overflow.
-  */
-  function add(uint256 a, uint256 b) internal pure returns (uint256) {
-    uint256 c = a + b;
-    require(c >= a);
-
-    return c;
-  }
-
-  /**
-  * @dev Divides two numbers and returns the remainder (unsigned integer modulo),
-  * reverts when dividing by zero.
-  */
-  function mod(uint256 a, uint256 b) internal pure returns (uint256) {
-    require(b != 0);
-    return a % b;
-  }
+    /**
+    * @dev Divides two unsigned integers and returns the remainder (unsigned integer modulo),
+    * reverts when dividing by zero.
+    */
+    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
+        require(b != 0);
+        return a % b;
+    }
 }

contracts/mocks/Acknowledger.sol

@@ -0,0 +1,19 @@
+pragma solidity ^0.5.0;
+
+contract Acknowledger {
+    event AcknowledgeFoo(uint256 a);
+    event AcknowledgeBarSingle(uint256 a);
+    event AcknowledgeBarDouble(uint256 a, uint256 b);
+
+    function foo(uint256 a) public {
+        emit AcknowledgeFoo(a);
+    }
+
+    function bar(uint256 a) public {
+        emit AcknowledgeBarSingle(a);
+    }
+
+    function bar(uint256 a, uint256 b) public {
+        emit AcknowledgeBarDouble(a, b);
+    }
+}

contracts/mocks/AddressImpl.sol

@@ -1,14 +1,9 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../utils/Address.sol";
 
 contract AddressImpl {
-  function isContract(address account)
-    external
-    view
-    returns (bool)
-  {
-    return Address.isContract(account); 
-  }
-  
+    function isContract(address account) external view returns (bool) {
+        return Address.isContract(account);
+    }
 }

contracts/mocks/AllowanceCrowdsaleImpl.sol

@@ -1,20 +1,14 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/IERC20.sol";
 import "../crowdsale/emission/AllowanceCrowdsale.sol";
 
 contract AllowanceCrowdsaleImpl is AllowanceCrowdsale {
-
-  constructor (
-    uint256 rate,
-    address wallet,
-    IERC20 token,
-    address tokenWallet
-  )
-    public
-    Crowdsale(rate, wallet, token)
-    AllowanceCrowdsale(tokenWallet)
-  {
-  }
-
+    constructor (uint256 rate, address payable wallet, IERC20 token, address tokenWallet)
+        public
+        Crowdsale(rate, wallet, token)
+        AllowanceCrowdsale(tokenWallet)
+    {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 }

contracts/mocks/ArraysImpl.sol

@@ -1,18 +1,17 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../utils/Arrays.sol";
 
 contract ArraysImpl {
+    using Arrays for uint256[];
 
-  using Arrays for uint256[];
+    uint256[] private array;
 
-  uint256[] private array;
+    constructor (uint256[] memory _array) public {
+        array = _array;
+    }
 
-  constructor(uint256[] _array) public {
-    array = _array;
-  }
-
-  function findUpperBound(uint256 _element) external view returns (uint256) {
-    return array.findUpperBound(_element);
-  }
+    function findUpperBound(uint256 _element) external view returns (uint256) {
+        return array.findUpperBound(_element);
+    }
 }

contracts/mocks/CappedCrowdsaleImpl.sol

@@ -1,20 +1,14 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/IERC20.sol";
 import "../crowdsale/validation/CappedCrowdsale.sol";
 
 contract CappedCrowdsaleImpl is CappedCrowdsale {
-
-  constructor (
-    uint256 rate,
-    address wallet,
-    IERC20 token,
-    uint256 cap
-  )
-    public
-    Crowdsale(rate, wallet, token)
-    CappedCrowdsale(cap)
-  {
-  }
-
+    constructor (uint256 rate, address payable wallet, IERC20 token, uint256 cap)
+        public
+        Crowdsale(rate, wallet, token)
+        CappedCrowdsale(cap)
+    {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 }

contracts/mocks/CapperRoleMock.sol

@@ -1,17 +1,18 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../access/roles/CapperRole.sol";
 
 contract CapperRoleMock is CapperRole {
-  function removeCapper(address account) public {
-    _removeCapper(account);
-  }
+    function removeCapper(address account) public {
+        _removeCapper(account);
+    }
 
-  function onlyCapperMock() public view onlyCapper {
-  }
+    function onlyCapperMock() public view onlyCapper {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 
-  // Causes a compilation error if super._removeCapper is not internal
-  function _removeCapper(address account) internal {
-    super._removeCapper(account);
-  }
+    // Causes a compilation error if super._removeCapper is not internal
+    function _removeCapper(address account) internal {
+        super._removeCapper(account);
+    }
 }

contracts/mocks/ConditionalEscrowMock.sol

@@ -1,16 +1,16 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../payment/escrow/ConditionalEscrow.sol";
 
 // mock class using ConditionalEscrow
 contract ConditionalEscrowMock is ConditionalEscrow {
-  mapping(address => bool) private _allowed;
+    mapping(address => bool) private _allowed;
 
-  function setAllowed(address payee, bool allowed) public {
-    _allowed[payee] = allowed;
-  }
+    function setAllowed(address payee, bool allowed) public {
+        _allowed[payee] = allowed;
+    }
 
-  function withdrawalAllowed(address payee) public view returns (bool) {
-    return _allowed[payee];
-  }
+    function withdrawalAllowed(address payee) public view returns (bool) {
+        return _allowed[payee];
+    }
 }

contracts/mocks/CounterImpl.sol

@@ -1,20 +1,17 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../drafts/Counter.sol";
 
 contract CounterImpl {
-  using Counter for Counter.Counter;
+    using Counter for Counter.Counter;
 
-  uint256 public theId;
+    uint256 public theId;
 
-  // use whatever key you want to track your counters
-  mapping(string => Counter.Counter) private _counters;
+    // use whatever key you want to track your counters
+    mapping(string => Counter.Counter) private _counters;
 
-  function doThing(string key)
-    public
-    returns (uint256)
-  {
-    theId = _counters[key].next();
-    return theId;
-  }
+    function doThing(string memory key) public returns (uint256) {
+        theId = _counters[key].next();
+        return theId;
+    }
 }

contracts/mocks/CrowdsaleMock.sol

@@ -1,9 +1,9 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../crowdsale/Crowdsale.sol";
 
 contract CrowdsaleMock is Crowdsale {
-  constructor(uint256 rate, address wallet, IERC20 token) public
-    Crowdsale(rate, wallet, token) {
-  }
+    constructor (uint256 rate, address payable wallet, IERC20 token) public Crowdsale(rate, wallet, token) {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 }

contracts/mocks/DetailedERC20Mock.sol

@@ -1,15 +1,13 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/ERC20.sol";
 import "../token/ERC20/ERC20Detailed.sol";
 
 contract ERC20DetailedMock is ERC20, ERC20Detailed {
-  constructor(
-    string name,
-    string symbol,
-    uint8 decimals
-  )
-    ERC20Detailed(name, symbol, decimals)
-    public
-  {}
+    constructor (string memory name, string memory symbol, uint8 decimals)
+        public
+        ERC20Detailed(name, symbol, decimals)
+    {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 }

contracts/mocks/ECDSAMock.sol

@@ -1,23 +1,15 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../cryptography/ECDSA.sol";
 
 contract ECDSAMock {
-  using ECDSA for bytes32;
+    using ECDSA for bytes32;
 
-  function recover(bytes32 hash, bytes signature)
-    public
-    pure
-    returns (address)
-  {
-    return hash.recover(signature);
-  }
+    function recover(bytes32 hash, bytes memory signature) public pure returns (address) {
+        return hash.recover(signature);
+    }
 
-  function toEthSignedMessageHash(bytes32 hash)
-    public
-    pure
-    returns (bytes32)
-  {
-    return hash.toEthSignedMessageHash();
-  }
+    function toEthSignedMessageHash(bytes32 hash) public pure returns (bytes32) {
+        return hash.toEthSignedMessageHash();
+    }
 }

contracts/mocks/ERC165/ERC165InterfacesSupported.sol

@@ -1,66 +1,56 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../../introspection/IERC165.sol";
 
 /**
  * https://github.com/ethereum/EIPs/blob/master/EIPS/eip-214.md#specification
- * > Any attempts to make state-changing operations inside an execution instance with STATIC set to true will instead throw an exception.
+ * > Any attempts to make state-changing operations inside an execution instance with STATIC set to true will instead
+ * throw an exception.
  * > These operations include [...], LOG0, LOG1, LOG2, [...]
  *
  * therefore, because this contract is staticcall'd we need to not emit events (which is how solidity-coverage works)
  * solidity-coverage ignores the /mocks folder, so we duplicate its implementation here to avoid instrumenting it
  */
 contract SupportsInterfaceWithLookupMock is IERC165 {
+    bytes4 public constant INTERFACE_ID_ERC165 = 0x01ffc9a7;
+    /**
+     * 0x01ffc9a7 ===
+     *     bytes4(keccak256('supportsInterface(bytes4)'))
+     */
 
-  bytes4 public constant InterfaceId_ERC165 = 0x01ffc9a7;
-  /**
-   * 0x01ffc9a7 ===
-   *   bytes4(keccak256('supportsInterface(bytes4)'))
-   */
+    /**
+     * @dev a mapping of interface id to whether or not it's supported
+     */
+    mapping(bytes4 => bool) private _supportedInterfaces;
 
-  /**
-   * @dev a mapping of interface id to whether or not it's supported
-   */
-  mapping(bytes4 => bool) private _supportedInterfaces;
+    /**
+     * @dev A contract implementing SupportsInterfaceWithLookup
+     * implement ERC165 itself
+     */
+    constructor () public {
+        _registerInterface(INTERFACE_ID_ERC165);
+    }
 
-  /**
-   * @dev A contract implementing SupportsInterfaceWithLookup
-   * implement ERC165 itself
-   */
-  constructor()
-    public
-  {
-    _registerInterface(InterfaceId_ERC165);
-  }
+    /**
+     * @dev implement supportsInterface(bytes4) using a lookup table
+     */
+    function supportsInterface(bytes4 interfaceId) external view returns (bool) {
+        return _supportedInterfaces[interfaceId];
+    }
 
-  /**
-   * @dev implement supportsInterface(bytes4) using a lookup table
-   */
-  function supportsInterface(bytes4 interfaceId)
-    external
-    view
-    returns (bool)
-  {
-    return _supportedInterfaces[interfaceId];
-  }
-
-  /**
-   * @dev private method for registering an interface
-   */
-  function _registerInterface(bytes4 interfaceId)
-    internal
-  {
-    require(interfaceId != 0xffffffff);
-    _supportedInterfaces[interfaceId] = true;
-  }
+    /**
+     * @dev private method for registering an interface
+     */
+    function _registerInterface(bytes4 interfaceId) internal {
+        require(interfaceId != 0xffffffff);
+        _supportedInterfaces[interfaceId] = true;
+    }
 }
 
 contract ERC165InterfacesSupported is SupportsInterfaceWithLookupMock {
-  constructor (bytes4[] interfaceIds)
-    public
-  {
-    for (uint256 i = 0; i < interfaceIds.length; i++) {
-      _registerInterface(interfaceIds[i]);
+    constructor (bytes4[] memory interfaceIds) public {
+        for (uint256 i = 0; i < interfaceIds.length; i++) {
+            _registerInterface(interfaceIds[i]);
+        }
     }
-  }
 }

contracts/mocks/ERC165/ERC165NotSupported.sol

@@ -1,5 +1,5 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 contract ERC165NotSupported {
-
+    // solhint-disable-previous-line no-empty-blocks
 }

contracts/mocks/ERC165CheckerMock.sol

@@ -1,31 +1,19 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../introspection/ERC165Checker.sol";
 
 contract ERC165CheckerMock {
-  using ERC165Checker for address;
+    using ERC165Checker for address;
 
-  function supportsERC165(address account)
-    public
-    view
-    returns (bool)
-  {
-    return account._supportsERC165();
-  }
+    function supportsERC165(address account) public view returns (bool) {
+        return account._supportsERC165();
+    }
 
-  function supportsInterface(address account, bytes4 interfaceId)
-    public
-    view
-    returns (bool)
-  {
-    return account._supportsInterface(interfaceId);
-  }
+    function supportsInterface(address account, bytes4 interfaceId) public view returns (bool) {
+        return account._supportsInterface(interfaceId);
+    }
 
-  function supportsAllInterfaces(address account, bytes4[] interfaceIds)
-    public
-    view
-    returns (bool)
-  {
-    return account._supportsAllInterfaces(interfaceIds);
-  }
+    function supportsAllInterfaces(address account, bytes4[] memory interfaceIds) public view returns (bool) {
+        return account._supportsAllInterfaces(interfaceIds);
+    }
 }

contracts/mocks/ERC165Mock.sol

@@ -1,11 +1,9 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../introspection/ERC165.sol";
 
 contract ERC165Mock is ERC165 {
-  function registerInterface(bytes4 interfaceId)
-    public
-  {
-    _registerInterface(interfaceId);
-  }
+    function registerInterface(bytes4 interfaceId) public {
+        _registerInterface(interfaceId);
+    }
 }

contracts/mocks/ERC20BurnableMock.sol

@@ -1,11 +1,9 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/ERC20Burnable.sol";
 
 contract ERC20BurnableMock is ERC20Burnable {
-
-  constructor(address initialAccount, uint256 initialBalance) public {
-    _mint(initialAccount, initialBalance);
-  }
-
+    constructor (address initialAccount, uint256 initialBalance) public {
+        _mint(initialAccount, initialBalance);
+    }
 }

contracts/mocks/ERC20MintableMock.sol

@@ -1,7 +1,8 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/ERC20Mintable.sol";
 import "./MinterRoleMock.sol";
 
 contract ERC20MintableMock is ERC20Mintable, MinterRoleMock {
+    // solhint-disable-previous-line no-empty-blocks
 }

contracts/mocks/ERC20Mock.sol

@@ -1,24 +1,22 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/ERC20.sol";
 
 // mock class using ERC20
 contract ERC20Mock is ERC20 {
+    constructor (address initialAccount, uint256 initialBalance) public {
+        _mint(initialAccount, initialBalance);
+    }
 
-  constructor(address initialAccount, uint256 initialBalance) public {
-    _mint(initialAccount, initialBalance);
-  }
+    function mint(address account, uint256 amount) public {
+        _mint(account, amount);
+    }
 
-  function mint(address account, uint256 amount) public {
-    _mint(account, amount);
-  }
-
-  function burn(address account, uint256 amount) public {
-    _burn(account, amount);
-  }
-
-  function burnFrom(address account, uint256 amount) public {
-    _burnFrom(account, amount);
-  }
+    function burn(address account, uint256 amount) public {
+        _burn(account, amount);
+    }
 
+    function burnFrom(address account, uint256 amount) public {
+        _burnFrom(account, amount);
+    }
 }

contracts/mocks/ERC20PausableMock.sol

@@ -1,13 +1,11 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/ERC20Pausable.sol";
 import "./PauserRoleMock.sol";
 
 // mock class using ERC20Pausable
 contract ERC20PausableMock is ERC20Pausable, PauserRoleMock {
-
-  constructor(address initialAccount, uint initialBalance) public {
-    _mint(initialAccount, initialBalance);
-  }
-
+    constructor (address initialAccount, uint initialBalance) public {
+        _mint(initialAccount, initialBalance);
+    }
 }

contracts/mocks/ERC20WithMetadataMock.sol

@@ -1,11 +1,10 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/ERC20.sol";
 import "../drafts/ERC1046/TokenMetadata.sol";
 
 contract ERC20WithMetadataMock is ERC20, ERC20WithMetadata {
-  constructor(string tokenURI) public
-    ERC20WithMetadata(tokenURI)
-  {
-  }
+    constructor (string memory tokenURI) public ERC20WithMetadata(tokenURI) {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 }

contracts/mocks/ERC721FullMock.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC721/ERC721Full.sol";
 import "../token/ERC721/ERC721Mintable.sol";
@@ -7,26 +7,23 @@ import "../token/ERC721/ERC721Burnable.sol";
 
 /**
  * @title ERC721FullMock
- * This mock just provides a public mint and burn functions for testing purposes,
- * and a public setter for metadata URI
+ * This mock just provides public functions for setting metadata URI, getting all tokens of an owner,
+ * checking token existence, removal of a token from an address
  */
-contract ERC721FullMock
-  is ERC721Full, ERC721Mintable, ERC721MetadataMintable, ERC721Burnable {
+contract ERC721FullMock is ERC721Full, ERC721Mintable, ERC721MetadataMintable, ERC721Burnable {
+    constructor (string memory name, string memory symbol) public ERC721Mintable() ERC721Full(name, symbol) {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 
-  constructor(string name, string symbol) public
-    ERC721Mintable()
-    ERC721Full(name, symbol)
-  {}
+    function exists(uint256 tokenId) public view returns (bool) {
+        return _exists(tokenId);
+    }
 
-  function exists(uint256 tokenId) public view returns (bool) {
-    return _exists(tokenId);
-  }
+    function tokensOfOwner(address owner) public view returns (uint256[] memory) {
+        return _tokensOfOwner(owner);
+    }
 
-  function setTokenURI(uint256 tokenId, string uri) public {
-    _setTokenURI(tokenId, uri);
-  }
-
-  function removeTokenFrom(address from, uint256 tokenId) public {
-    _removeTokenFrom(from, tokenId);
-  }
+    function setTokenURI(uint256 tokenId, string memory uri) public {
+        _setTokenURI(tokenId, uri);
+    }
 }

contracts/mocks/ERC721MintableBurnableImpl.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC721/ERC721Full.sol";
 import "../token/ERC721/ERC721Mintable.sol";
@@ -8,13 +8,8 @@ import "../token/ERC721/ERC721Burnable.sol";
 /**
  * @title ERC721MintableBurnableImpl
  */
-contract ERC721MintableBurnableImpl
-  is ERC721Full, ERC721Mintable, ERC721MetadataMintable, ERC721Burnable {
-
-  constructor()
-    ERC721Mintable()
-    ERC721Full("Test", "TEST")
-    public
-  {
-  }
+contract ERC721MintableBurnableImpl is ERC721Full, ERC721Mintable, ERC721MetadataMintable, ERC721Burnable {
+    constructor () public ERC721Mintable() ERC721Full("Test", "TEST") {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 }

contracts/mocks/ERC721Mock.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC721/ERC721.sol";
 
@@ -7,11 +7,15 @@ import "../token/ERC721/ERC721.sol";
  * This mock just provides a public mint and burn functions for testing purposes
  */
 contract ERC721Mock is ERC721 {
-  function mint(address to, uint256 tokenId) public {
-    _mint(to, tokenId);
-  }
+    function mint(address to, uint256 tokenId) public {
+        _mint(to, tokenId);
+    }
 
-  function burn(uint256 tokenId) public {
-    _burn(ownerOf(tokenId), tokenId);
-  }
+    function burn(address owner, uint256 tokenId) public {
+        _burn(owner, tokenId);
+    }
+
+    function burn(uint256 tokenId) public {
+        _burn(tokenId);
+    }
 }

contracts/mocks/ERC721PausableMock.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC721/ERC721Pausable.sol";
 import "./PauserRoleMock.sol";
@@ -8,15 +8,15 @@ import "./PauserRoleMock.sol";
  * This mock just provides a public mint, burn and exists functions for testing purposes
  */
 contract ERC721PausableMock is ERC721Pausable, PauserRoleMock {
-  function mint(address to, uint256 tokenId) public {
-    super._mint(to, tokenId);
-  }
+    function mint(address to, uint256 tokenId) public {
+        super._mint(to, tokenId);
+    }
 
-  function burn(uint256 tokenId) public {
-    super._burn(ownerOf(tokenId), tokenId);
-  }
+    function burn(uint256 tokenId) public {
+        super._burn(tokenId);
+    }
 
-  function exists(uint256 tokenId) public view returns (bool) {
-    return super._exists(tokenId);
-  }
+    function exists(uint256 tokenId) public view returns (bool) {
+        return super._exists(tokenId);
+    }
 }

contracts/mocks/ERC721ReceiverMock.sol

@@ -1,41 +1,23 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC721/IERC721Receiver.sol";
 
 contract ERC721ReceiverMock is IERC721Receiver {
-  bytes4 private _retval;
-  bool private _reverts;
+    bytes4 private _retval;
+    bool private _reverts;
 
-  event Received(
-    address operator,
-    address from,
-    uint256 tokenId,
-    bytes data,
-    uint256 gas
-  );
+    event Received(address operator, address from, uint256 tokenId, bytes data, uint256 gas);
 
-  constructor(bytes4 retval, bool reverts) public {
-    _retval = retval;
-    _reverts = reverts;
-  }
+    constructor (bytes4 retval, bool reverts) public {
+        _retval = retval;
+        _reverts = reverts;
+    }
 
-  function onERC721Received(
-    address operator,
-    address from,
-    uint256 tokenId,
-    bytes data
-  )
-    public
-    returns(bytes4)
-  {
-    require(!_reverts);
-    emit Received(
-      operator,
-      from,
-      tokenId,
-      data,
-      gasleft() // msg.gas was deprecated in solidityv0.4.21
-    );
-    return _retval;
-  }
+    function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)
+        public returns (bytes4)
+    {
+        require(!_reverts);
+        emit Received(operator, from, tokenId, data, gasleft());
+        return _retval;
+    }
 }

contracts/mocks/EventEmitter.sol

@@ -1,62 +1,73 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 contract EventEmitter {
-  event Argumentless();
-  event ShortUint(uint8 value);
-  event ShortInt(int8 value);
-  event LongUint(uint256 value);
-  event LongInt(int256 value);
-  event Address(address value);
-  event Boolean(bool value);
-  event String(string value);
-  event LongUintBooleanString(
-    uint256 uintValue,
-    bool booleanValue,
-    string stringValue
-  );
+    event Argumentless();
+    event ShortUint(uint8 value);
+    event ShortInt(int8 value);
+    event LongUint(uint256 value);
+    event LongInt(int256 value);
+    event Address(address value);
+    event Boolean(bool value);
+    event String(string value);
+    event LongUintBooleanString(uint256 uintValue, bool booleanValue, string stringValue);
 
-  function emitArgumentless() public {
-    emit Argumentless();
-  }
+    constructor (uint8 uintValue, bool booleanValue, string memory stringValue) public {
+        emit ShortUint(uintValue);
+        emit Boolean(booleanValue);
+        emit String(stringValue);
+    }
 
-  function emitShortUint(uint8 value) public {
-    emit ShortUint(value);
-  }
+    function emitArgumentless() public {
+        emit Argumentless();
+    }
 
-  function emitShortInt(int8 value) public {
-    emit ShortInt(value);
-  }
+    function emitShortUint(uint8 value) public {
+        emit ShortUint(value);
+    }
 
-  function emitLongUint(uint256 value) public {
-    emit LongUint(value);
-  }
+    function emitShortInt(int8 value) public {
+        emit ShortInt(value);
+    }
 
-  function emitLongInt(int256 value) public {
-    emit LongInt(value);
-  }
+    function emitLongUint(uint256 value) public {
+        emit LongUint(value);
+    }
 
-  function emitAddress(address value) public {
-    emit Address(value);
-  }
+    function emitLongInt(int256 value) public {
+        emit LongInt(value);
+    }
 
-  function emitBoolean(bool value) public {
-    emit Boolean(value);
-  }
+    function emitAddress(address value) public {
+        emit Address(value);
+    }
 
-  function emitString(string value) public {
-    emit String(value);
-  }
+    function emitBoolean(bool value) public {
+        emit Boolean(value);
+    }
 
-  function emitLongUintBooleanString(
-    uint256 uintValue,
-    bool booleanValue,
-    string stringValue)
-  public {
-    emit LongUintBooleanString(uintValue, booleanValue, stringValue);
-  }
+    function emitString(string memory value) public {
+        emit String(value);
+    }
 
-  function emitLongUintAndBoolean(uint256 uintValue, bool boolValue) public {
-    emit LongUint(uintValue);
-    emit Boolean(boolValue);
-  }
+    function emitLongUintBooleanString(uint256 uintValue, bool booleanValue, string memory stringValue) public {
+        emit LongUintBooleanString(uintValue, booleanValue, stringValue);
+    }
+
+    function emitLongUintAndBoolean(uint256 uintValue, bool boolValue) public {
+        emit LongUint(uintValue);
+        emit Boolean(boolValue);
+    }
+
+    function emitStringAndEmitIndirectly(string memory value, IndirectEventEmitter emitter) public {
+        emit String(value);
+        emitter.emitStringIndirectly(value);
+    }
+}
+
+contract IndirectEventEmitter {
+    event IndirectString(string value);
+
+    function emitStringIndirectly(string memory value) public {
+        emit IndirectString(value);
+    }
 }

contracts/mocks/Failer.sol

@@ -0,0 +1,23 @@
+pragma solidity ^0.5.0;
+
+contract Failer {
+    uint256[] private array;
+
+    function dontFail() public pure {
+        // solhint-disable-previous-line no-empty-blocks
+    }
+
+    function failWithRevert() public pure {
+        revert();
+    }
+
+    function failWithThrow() public pure {
+        assert(false);
+    }
+
+    function failWithOutOfGas() public {
+        for (uint256 i = 0; i < 2**200; ++i) {
+            array.push(i);
+        }
+    }
+}

contracts/mocks/FinalizableCrowdsaleImpl.sol

@@ -1,21 +1,14 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/IERC20.sol";
 import "../crowdsale/distribution/FinalizableCrowdsale.sol";
 
 contract FinalizableCrowdsaleImpl is FinalizableCrowdsale {
-
-  constructor (
-    uint256 openingTime,
-    uint256 closingTime,
-    uint256 rate,
-    address wallet,
-    IERC20 token
-  )
-    public
-    Crowdsale(rate, wallet, token)
-    TimedCrowdsale(openingTime, closingTime)
-  {
-  }
-
+    constructor (uint256 openingTime, uint256 closingTime, uint256 rate, address payable wallet, IERC20 token)
+        public
+        Crowdsale(rate, wallet, token)
+        TimedCrowdsale(openingTime, closingTime)
+    {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 }

contracts/mocks/IncreasingPriceCrowdsaleImpl.sol

@@ -1,23 +1,22 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../crowdsale/price/IncreasingPriceCrowdsale.sol";
 import "../math/SafeMath.sol";
 
 contract IncreasingPriceCrowdsaleImpl is IncreasingPriceCrowdsale {
-
-  constructor (
-    uint256 openingTime,
-    uint256 closingTime,
-    address wallet,
-    IERC20 token,
-    uint256 initialRate,
-    uint256 finalRate
-  )
-    public
-    Crowdsale(initialRate, wallet, token)
-    TimedCrowdsale(openingTime, closingTime)
-    IncreasingPriceCrowdsale(initialRate, finalRate)
-  {
-  }
-
+    constructor (
+        uint256 openingTime,
+        uint256 closingTime,
+        address payable wallet,
+        IERC20 token,
+        uint256 initialRate,
+        uint256 finalRate
+    )
+        public
+        Crowdsale(initialRate, wallet, token)
+        TimedCrowdsale(openingTime, closingTime)
+        IncreasingPriceCrowdsale(initialRate, finalRate)
+    {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 }

contracts/mocks/IndividuallyCappedCrowdsaleImpl.sol

@@ -1,19 +1,11 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/IERC20.sol";
 import "../crowdsale/validation/IndividuallyCappedCrowdsale.sol";
 import "./CapperRoleMock.sol";
 
-contract IndividuallyCappedCrowdsaleImpl
-  is IndividuallyCappedCrowdsale, CapperRoleMock {
-
-  constructor(
-    uint256 rate,
-    address wallet,
-    IERC20 token
-  )
-    public
-    Crowdsale(rate, wallet, token)
-  {
-  }
+contract IndividuallyCappedCrowdsaleImpl is IndividuallyCappedCrowdsale, CapperRoleMock {
+    constructor (uint256 rate, address payable wallet, IERC20 token) public Crowdsale(rate, wallet, token) {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 }

contracts/mocks/MathMock.sol

@@ -1,17 +1,17 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../math/Math.sol";
 
 contract MathMock {
-  function max(uint256 a, uint256 b) public pure returns (uint256) {
-    return Math.max(a, b);
-  }
+    function max(uint256 a, uint256 b) public pure returns (uint256) {
+        return Math.max(a, b);
+    }
 
-  function min(uint256 a, uint256 b) public pure returns (uint256) {
-    return Math.min(a, b);
-  }
+    function min(uint256 a, uint256 b) public pure returns (uint256) {
+        return Math.min(a, b);
+    }
 
-  function average(uint256 a, uint256 b) public pure returns (uint256) {
-    return Math.average(a, b);
-  }
+    function average(uint256 a, uint256 b) public pure returns (uint256) {
+        return Math.average(a, b);
+    }
 }

contracts/mocks/MerkleProofWrapper.sol

@@ -1,18 +1,9 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import { MerkleProof } from "../cryptography/MerkleProof.sol";
 
 contract MerkleProofWrapper {
-
-  function verify(
-    bytes32[] proof,
-    bytes32 root,
-    bytes32 leaf
-  )
-    public
-    pure
-    returns (bool)
-  {
-    return MerkleProof.verify(proof, root, leaf);
-  }
+    function verify(bytes32[] memory proof, bytes32 root, bytes32 leaf) public pure returns (bool) {
+        return MerkleProof.verify(proof, root, leaf);
+    }
 }

contracts/mocks/MintedCrowdsaleImpl.sol

@@ -1,18 +1,10 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/ERC20Mintable.sol";
 import "../crowdsale/emission/MintedCrowdsale.sol";
 
 contract MintedCrowdsaleImpl is MintedCrowdsale {
-
-  constructor (
-    uint256 rate,
-    address wallet,
-    ERC20Mintable token
-  )
-    public
-    Crowdsale(rate, wallet, token)
-  {
-  }
-
+    constructor (uint256 rate, address payable wallet, ERC20Mintable token) public Crowdsale(rate, wallet, token) {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 }

contracts/mocks/MinterRoleMock.sol

@@ -1,17 +1,18 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../access/roles/MinterRole.sol";
 
 contract MinterRoleMock is MinterRole {
-  function removeMinter(address account) public {
-    _removeMinter(account);
-  }
+    function removeMinter(address account) public {
+        _removeMinter(account);
+    }
 
-  function onlyMinterMock() public view onlyMinter {
-  }
+    function onlyMinterMock() public view onlyMinter {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 
-  // Causes a compilation error if super._removeMinter is not internal
-  function _removeMinter(address account) internal {
-    super._removeMinter(account);
-  }
+    // Causes a compilation error if super._removeMinter is not internal
+    function _removeMinter(address account) internal {
+        super._removeMinter(account);
+    }
 }

contracts/mocks/OwnableInterfaceId.sol

@@ -0,0 +1,15 @@
+pragma solidity ^0.5.0;
+
+import "../ownership/Ownable.sol";
+
+/**
+ * @title Ownable interface id calculator.
+ * @dev See the EIP165 specification for more information:
+ * https://github.com/ethereum/EIPs/blob/master/EIPS/eip-165.md#specification
+ */
+contract OwnableInterfaceId {
+    function getInterfaceId() public pure returns (bytes4) {
+        Ownable i;
+        return i.owner.selector ^ i.isOwner.selector ^ i.renounceOwnership.selector ^ i.transferOwnership.selector;
+    }
+}

contracts/mocks/OwnableMock.sol

@@ -1,6 +1,7 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../ownership/Ownable.sol";
 
 contract OwnableMock is Ownable {
+    // solhint-disable-previous-line no-empty-blocks
 }

contracts/mocks/PausableCrowdsaleImpl.sol

@@ -0,0 +1,10 @@
+pragma solidity ^0.5.0;
+
+import "../token/ERC20/ERC20.sol";
+import "../crowdsale/validation/PausableCrowdsale.sol";
+
+contract PausableCrowdsaleImpl is PausableCrowdsale {
+    constructor (uint256 _rate, address payable _wallet, ERC20 _token) public Crowdsale(_rate, _wallet, _token) {
+        // solhint-disable-previous-line no-empty-blocks
+    }
+}

contracts/mocks/PausableMock.sol

@@ -1,24 +1,23 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../lifecycle/Pausable.sol";
 import "./PauserRoleMock.sol";
 
 // mock class using Pausable
 contract PausableMock is Pausable, PauserRoleMock {
-  bool public drasticMeasureTaken;
-  uint256 public count;
+    bool public drasticMeasureTaken;
+    uint256 public count;
 
-  constructor() public {
-    drasticMeasureTaken = false;
-    count = 0;
-  }
+    constructor () public {
+        drasticMeasureTaken = false;
+        count = 0;
+    }
 
-  function normalProcess() external whenNotPaused {
-    count++;
-  }
-
-  function drasticMeasure() external whenPaused {
-    drasticMeasureTaken = true;
-  }
+    function normalProcess() external whenNotPaused {
+        count++;
+    }
 
+    function drasticMeasure() external whenPaused {
+        drasticMeasureTaken = true;
+    }
 }

contracts/mocks/PauserRoleMock.sol

@@ -1,17 +1,18 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../access/roles/PauserRole.sol";
 
 contract PauserRoleMock is PauserRole {
-  function removePauser(address account) public {
-    _removePauser(account);
-  }
+    function removePauser(address account) public {
+        _removePauser(account);
+    }
 
-  function onlyPauserMock() public view onlyPauser {
-  }
+    function onlyPauserMock() public view onlyPauser {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 
-  // Causes a compilation error if super._removePauser is not internal
-  function _removePauser(address account) internal {
-    super._removePauser(account);
-  }
+    // Causes a compilation error if super._removePauser is not internal
+    function _removePauser(address account) internal {
+        super._removePauser(account);
+    }
 }

contracts/mocks/PostDeliveryCrowdsaleImpl.sol

@@ -1,21 +1,14 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/IERC20.sol";
 import "../crowdsale/distribution/PostDeliveryCrowdsale.sol";
 
 contract PostDeliveryCrowdsaleImpl is PostDeliveryCrowdsale {
-
-  constructor (
-    uint256 openingTime,
-    uint256 closingTime,
-    uint256 rate,
-    address wallet,
-    IERC20 token
-  )
-    public
-    TimedCrowdsale(openingTime, closingTime)
-    Crowdsale(rate, wallet, token)
-  {
-  }
-
+    constructor (uint256 openingTime, uint256 closingTime, uint256 rate, address payable wallet, IERC20 token)
+        public
+        TimedCrowdsale(openingTime, closingTime)
+        Crowdsale(rate, wallet, token)
+    {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 }

contracts/mocks/PullPaymentMock.sol

@@ -1,15 +1,15 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../payment/PullPayment.sol";
 
 // mock class using PullPayment
 contract PullPaymentMock is PullPayment {
+    constructor () public payable {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 
-  constructor() public payable { }
-
-  // test helper function to call asyncTransfer
-  function callTransfer(address dest, uint256 amount) public {
-    _asyncTransfer(dest, amount);
-  }
-
+    // test helper function to call asyncTransfer
+    function callTransfer(address dest, uint256 amount) public {
+        _asyncTransfer(dest, amount);
+    }
 }

contracts/mocks/ReentrancyAttack.sol

@@ -1,10 +1,9 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 contract ReentrancyAttack {
-
-  function callSender(bytes4 data) public {
-    // solium-disable-next-line security/no-low-level-calls
-    require(msg.sender.call(abi.encodeWithSelector(data)));
-  }
-
+    function callSender(bytes4 data) public {
+        // solhint-disable-next-line avoid-low-level-calls
+        (bool success,) = msg.sender.call(abi.encodeWithSelector(data));
+        require(success);
+    }
 }

contracts/mocks/ReentrancyMock.sol

@@ -1,44 +1,42 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../utils/ReentrancyGuard.sol";
 import "./ReentrancyAttack.sol";
 
 contract ReentrancyMock is ReentrancyGuard {
+    uint256 public counter;
 
-  uint256 public counter;
-
-  constructor() public {
-    counter = 0;
-  }
-
-  function callback() external nonReentrant {
-    count();
-  }
-
-  function countLocalRecursive(uint256 n) public nonReentrant {
-    if (n > 0) {
-      count();
-      countLocalRecursive(n - 1);
+    constructor () public {
+        counter = 0;
     }
-  }
 
-  function countThisRecursive(uint256 n) public nonReentrant {
-    if (n > 0) {
-      count();
-      // solium-disable-next-line security/no-low-level-calls
-      bool result = address(this).call(abi.encodeWithSignature("countThisRecursive(uint256)", n - 1));
-      require(result == true);
+    function callback() external nonReentrant {
+        count();
     }
-  }
 
-  function countAndCall(ReentrancyAttack attacker) public nonReentrant {
-    count();
-    bytes4 func = bytes4(keccak256("callback()"));
-    attacker.callSender(func);
-  }
+    function countLocalRecursive(uint256 n) public nonReentrant {
+        if (n > 0) {
+            count();
+            countLocalRecursive(n - 1);
+        }
+    }
 
-  function count() private {
-    counter += 1;
-  }
+    function countThisRecursive(uint256 n) public nonReentrant {
+        if (n > 0) {
+            count();
+            // solhint-disable-next-line avoid-low-level-calls
+            (bool success,) = address(this).call(abi.encodeWithSignature("countThisRecursive(uint256)", n - 1));
+            require(success);
+        }
+    }
 
+    function countAndCall(ReentrancyAttack attacker) public nonReentrant {
+        count();
+        bytes4 func = bytes4(keccak256("callback()"));
+        attacker.callSender(func);
+    }
+
+    function count() private {
+        counter += 1;
+    }
 }

contracts/mocks/RefundableCrowdsaleImpl.sol

@@ -1,23 +1,22 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
-import "../token/ERC20/ERC20Mintable.sol";
+import "../token/ERC20/IERC20.sol";
 import "../crowdsale/distribution/RefundableCrowdsale.sol";
 
 contract RefundableCrowdsaleImpl is RefundableCrowdsale {
-
-  constructor (
-    uint256 openingTime,
-    uint256 closingTime,
-    uint256 rate,
-    address wallet,
-    ERC20Mintable token,
-    uint256 goal
-  )
-    public
-    Crowdsale(rate, wallet, token)
-    TimedCrowdsale(openingTime, closingTime)
-    RefundableCrowdsale(goal)
-  {
-  }
-
+    constructor (
+        uint256 openingTime,
+        uint256 closingTime,
+        uint256 rate,
+        address payable wallet,
+        IERC20 token,
+        uint256 goal
+    )
+        public
+        Crowdsale(rate, wallet, token)
+        TimedCrowdsale(openingTime, closingTime)
+        RefundableCrowdsale(goal)
+    {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 }

contracts/mocks/RefundablePostDeliveryCrowdsaleImpl.sol

@@ -0,0 +1,22 @@
+pragma solidity ^0.5.0;
+
+import "../token/ERC20/IERC20.sol";
+import "../crowdsale/distribution/RefundablePostDeliveryCrowdsale.sol";
+
+contract RefundablePostDeliveryCrowdsaleImpl is RefundablePostDeliveryCrowdsale {
+    constructor (
+        uint256 openingTime,
+        uint256 closingTime,
+        uint256 rate,
+        address payable wallet,
+        IERC20 token,
+        uint256 goal
+    )
+        public
+        Crowdsale(rate, wallet, token)
+        TimedCrowdsale(openingTime, closingTime)
+        RefundableCrowdsale(goal)
+    {
+        // solhint-disable-previous-line no-empty-blocks
+    }
+}

contracts/mocks/RolesMock.sol

@@ -1,21 +1,21 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../access/Roles.sol";
 
 contract RolesMock {
-  using Roles for Roles.Role;
+    using Roles for Roles.Role;
 
-  Roles.Role private dummyRole;
+    Roles.Role private dummyRole;
 
-  function add(address account) public {
-    dummyRole.add(account);
-  }
+    function add(address account) public {
+        dummyRole.add(account);
+    }
 
-  function remove(address account) public {
-    dummyRole.remove(account);
-  }
+    function remove(address account) public {
+        dummyRole.remove(account);
+    }
 
-  function has(address account) public view returns (bool) {
-    return dummyRole.has(account);
-  }
+    function has(address account) public view returns (bool) {
+        return dummyRole.has(account);
+    }
 }

contracts/mocks/SafeERC20Helper.sol

@@ -1,112 +1,108 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../token/ERC20/IERC20.sol";
 import "../token/ERC20/SafeERC20.sol";
 
 contract ERC20FailingMock {
-  uint256 private _allowance;
+    uint256 private _allowance;
 
-  function transfer(address, uint256) public returns (bool) {
-    return false;
-  }
+    function transfer(address, uint256) public returns (bool) {
+        return false;
+    }
 
-  function transferFrom(address, address, uint256) public returns (bool) {
-    return false;
-  }
+    function transferFrom(address, address, uint256) public returns (bool) {
+        return false;
+    }
 
-  function approve(address, uint256) public returns (bool) {
-    return false;
-  }
+    function approve(address, uint256) public returns (bool) {
+        return false;
+    }
 
-  function allowance(address, address) public view returns (uint256) {
-    return 0;
-  }
+    function allowance(address, address) public view returns (uint256) {
+        return 0;
+    }
 }
 
 contract ERC20SucceedingMock {
-  uint256 private _allowance;
+    uint256 private _allowance;
 
-  function transfer(address, uint256) public returns (bool) {
-    return true;
-  }
+    function transfer(address, uint256) public returns (bool) {
+        return true;
+    }
 
-  function transferFrom(address, address, uint256) public returns (bool) {
-    return true;
-  }
+    function transferFrom(address, address, uint256) public returns (bool) {
+        return true;
+    }
 
-  function approve(address, uint256) public returns (bool) {
-    return true;
-  }
+    function approve(address, uint256) public returns (bool) {
+        return true;
+    }
 
-  function setAllowance(uint256 allowance_) public {
-    _allowance = allowance_;
-  }
+    function setAllowance(uint256 allowance_) public {
+        _allowance = allowance_;
+    }
 
-  function allowance(address, address) public view returns (uint256) {
-    return _allowance;
-  }
+    function allowance(address, address) public view returns (uint256) {
+        return _allowance;
+    }
 }
 
 contract SafeERC20Helper {
-  using SafeERC20 for IERC20;
+    using SafeERC20 for IERC20;
 
-  IERC20 private _failing;
-  IERC20 private _succeeding;
+    IERC20 private _failing;
+    IERC20 private _succeeding;
 
-  constructor() public {
-    _failing = IERC20(new ERC20FailingMock());
-    _succeeding = IERC20(new ERC20SucceedingMock());
-  }
+    constructor () public {
+        _failing = IERC20(address(new ERC20FailingMock()));
+        _succeeding = IERC20(address(new ERC20SucceedingMock()));
+    }
 
-  // Using _failing
+    function doFailingTransfer() public {
+        _failing.safeTransfer(address(0), 0);
+    }
 
-  function doFailingTransfer() public {
-    _failing.safeTransfer(address(0), 0);
-  }
+    function doFailingTransferFrom() public {
+        _failing.safeTransferFrom(address(0), address(0), 0);
+    }
 
-  function doFailingTransferFrom() public {
-    _failing.safeTransferFrom(address(0), address(0), 0);
-  }
+    function doFailingApprove() public {
+        _failing.safeApprove(address(0), 0);
+    }
 
-  function doFailingApprove() public {
-    _failing.safeApprove(address(0), 0);
-  }
+    function doFailingIncreaseAllowance() public {
+        _failing.safeIncreaseAllowance(address(0), 0);
+    }
 
-  function doFailingIncreaseAllowance() public {
-    _failing.safeIncreaseAllowance(address(0), 0);
-  }
+    function doFailingDecreaseAllowance() public {
+        _failing.safeDecreaseAllowance(address(0), 0);
+    }
 
-  function doFailingDecreaseAllowance() public {
-    _failing.safeDecreaseAllowance(address(0), 0);
-  }
+    function doSucceedingTransfer() public {
+        _succeeding.safeTransfer(address(0), 0);
+    }
 
-  // Using _succeeding
+    function doSucceedingTransferFrom() public {
+        _succeeding.safeTransferFrom(address(0), address(0), 0);
+    }
 
-  function doSucceedingTransfer() public {
-    _succeeding.safeTransfer(address(0), 0);
-  }
+    function doSucceedingApprove(uint256 amount) public {
+        _succeeding.safeApprove(address(0), amount);
+    }
 
-  function doSucceedingTransferFrom() public {
-    _succeeding.safeTransferFrom(address(0), address(0), 0);
-  }
+    function doSucceedingIncreaseAllowance(uint256 amount) public {
+        _succeeding.safeIncreaseAllowance(address(0), amount);
+    }
 
-  function doSucceedingApprove(uint256 amount) public {
-    _succeeding.safeApprove(address(0), amount);
-  }
+    function doSucceedingDecreaseAllowance(uint256 amount) public {
+        _succeeding.safeDecreaseAllowance(address(0), amount);
+    }
 
-  function doSucceedingIncreaseAllowance(uint256 amount) public {
-    _succeeding.safeIncreaseAllowance(address(0), amount);
-  }
+    function setAllowance(uint256 allowance_) public {
+        ERC20SucceedingMock(address(_succeeding)).setAllowance(allowance_);
+    }
 
-  function doSucceedingDecreaseAllowance(uint256 amount) public {
-    _succeeding.safeDecreaseAllowance(address(0), amount);
-  }
-
-  function setAllowance(uint256 allowance_) public {
-    ERC20SucceedingMock(_succeeding).setAllowance(allowance_);
-  }
-
-  function allowance() public view returns (uint256) {
-    return _succeeding.allowance(address(0), address(0));
-  }
+    function allowance() public view returns (uint256) {
+        return _succeeding.allowance(address(0), address(0));
+    }
 }

contracts/mocks/SafeMathMock.sol

@@ -1,26 +1,25 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../math/SafeMath.sol";
 
 contract SafeMathMock {
+    function mul(uint256 a, uint256 b) public pure returns (uint256) {
+        return SafeMath.mul(a, b);
+    }
 
-  function mul(uint256 a, uint256 b) public pure returns (uint256) {
-    return SafeMath.mul(a, b);
-  }
+    function div(uint256 a, uint256 b) public pure returns (uint256) {
+        return SafeMath.div(a, b);
+    }
 
-  function div(uint256 a, uint256 b) public pure returns (uint256) {
-    return SafeMath.div(a, b);
-  }
+    function sub(uint256 a, uint256 b) public pure returns (uint256) {
+        return SafeMath.sub(a, b);
+    }
 
-  function sub(uint256 a, uint256 b) public pure returns (uint256) {
-    return SafeMath.sub(a, b);
-  }
+    function add(uint256 a, uint256 b) public pure returns (uint256) {
+        return SafeMath.add(a, b);
+    }
 
-  function add(uint256 a, uint256 b) public pure returns (uint256) {
-    return SafeMath.add(a, b);
-  }
-
-  function mod(uint256 a, uint256 b) public pure returns (uint256) {
-    return SafeMath.mod(a, b);
-  }
+    function mod(uint256 a, uint256 b) public pure returns (uint256) {
+        return SafeMath.mod(a, b);
+    }
 }

contracts/mocks/SecondaryMock.sol

@@ -1,8 +1,9 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../ownership/Secondary.sol";
 
 contract SecondaryMock is Secondary {
-  function onlyPrimaryMock() public view onlyPrimary {
-  }
+    function onlyPrimaryMock() public view onlyPrimary {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 }

contracts/mocks/SignatureBouncerMock.sol

@@ -1,73 +1,50 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../drafts/SignatureBouncer.sol";
 import "./SignerRoleMock.sol";
 
 contract SignatureBouncerMock is SignatureBouncer, SignerRoleMock {
-  function checkValidSignature(address account, bytes signature)
-    public
-    view
-    returns (bool)
-  {
-    return _isValidSignature(account, signature);
-  }
+    function checkValidSignature(address account, bytes memory signature)
+        public view returns (bool)
+    {
+        return _isValidSignature(account, signature);
+    }
 
-  function onlyWithValidSignature(bytes signature)
-    public
-    onlyValidSignature(signature)
-    view
-  {
+    function onlyWithValidSignature(bytes memory signature)
+        public onlyValidSignature(signature) view
+    {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 
-  }
+    function checkValidSignatureAndMethod(address account, bytes memory signature)
+        public view returns (bool)
+    {
+        return _isValidSignatureAndMethod(account, signature);
+    }
 
-  function checkValidSignatureAndMethod(address account, bytes signature)
-    public
-    view
-    returns (bool)
-  {
-    return _isValidSignatureAndMethod(account, signature);
-  }
+    function onlyWithValidSignatureAndMethod(bytes memory signature)
+        public onlyValidSignatureAndMethod(signature) view
+    {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 
-  function onlyWithValidSignatureAndMethod(bytes signature)
-    public
-    onlyValidSignatureAndMethod(signature)
-    view
-  {
+    function checkValidSignatureAndData(address account, bytes memory, uint, bytes memory signature)
+        public view returns (bool)
+    {
+        return _isValidSignatureAndData(account, signature);
+    }
 
-  }
+    function onlyWithValidSignatureAndData(uint, bytes memory signature)
+        public onlyValidSignatureAndData(signature) view
+    {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 
-  function checkValidSignatureAndData(
-    address account,
-    bytes,
-    uint,
-    bytes signature
-  )
-    public
-    view
-    returns (bool)
-  {
-    return _isValidSignatureAndData(account, signature);
-  }
+    function theWrongMethod(bytes memory) public pure {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 
-  function onlyWithValidSignatureAndData(uint, bytes signature)
-    public
-    onlyValidSignatureAndData(signature)
-    view
-  {
-
-  }
-
-  function theWrongMethod(bytes)
-    public
-    pure
-  {
-
-  }
-
-  function tooShortMsgData()
-    public
-    onlyValidSignatureAndData("")
-    view
-  {
-  }
+    function tooShortMsgData() public onlyValidSignatureAndData("") view {
+        // solhint-disable-previous-line no-empty-blocks
+    }
 }

contracts/mocks/SignedSafeMathMock.sol

@@ -0,0 +1,21 @@
+pragma solidity ^0.5.0;
+
+import "../drafts/SignedSafeMath.sol";
+
+contract SignedSafeMathMock {
+    function mul(int256 a, int256 b) public pure returns (int256) {
+        return SignedSafeMath.mul(a, b);
+    }
+
+    function div(int256 a, int256 b) public pure returns (int256) {
+        return SignedSafeMath.div(a, b);
+    }
+
+    function sub(int256 a, int256 b) public pure returns (int256) {
+        return SignedSafeMath.sub(a, b);
+    }
+
+    function add(int256 a, int256 b) public pure returns (int256) {
+        return SignedSafeMath.add(a, b);
+    }
+}