* make _tokenId indexed in Transfer and Approval events
via: https://github.com/ethereum/EIPs/pull/1124/files
* fix: make name() and symbol() external instead of public
* feat: implement ERC721's ERC165
* feat: erc165 tests
* fix: don't use chai-as-promised in direct await
* fix: reorganize to /introspection
* feat: abstract all erc165 tests to a behavior
* feat: disallow registering 0xffffffff
* Refactoring Superuser contract to allow Owners to transfer ownership when they are not superusers #50
* Refactoring tests to create a contract instance for each of them #50
* added the RBACMintableToken
* added MintedCrowdsale with RBACMintableToken test
* added a mintable behaviour for tests
* moved minting tests in behaviour
* created a minted crowdsale behaviour to be tested with both mintable and rbacmintable token
* Update ERC827.sol to not use function overloading
* updated tests for erc827 function name changes
* fixed broken test
* removed findMethod from erc827 tests that is no longer necessary
* Add StandardBurnableToken implementation
BurnableToken that extends from StandardToken and adds a
burnFrom method that decrements allowance. Equivalent to
a transferFrom plus burn in a single operation.
* Return event object from expectEvent helper
* Add comment on Approval event in burnFrom function
* Improvements on burnable token tests
- Inject initial balance as a parameter to the behaviour
- Use expectEvent helper for assertions on events
- Use chai bignumber for numbers
- Change to bdd-style assertions
* fix: clean up solium linting errors
* fix: make various contracts natspec compliant
* fix: this.balance deprecated; convert to address(this).balance
* fix: contract.call deprecated and switch to gasleft()
* fix: ignore empty block rule project-wide
* fix: add ignore cases for the rest of the linting warnings
* Update to ganache-cli v6.1.0 and truffle v4.1.0
* Update to stable version of ganache-cli
* fix: update event emission warning
- Fix event emission warnings for solidity 4.21 after truffle has been
updated to use this version
* fix pr review comments
* update to truffle v4.1.5
* update package-lock
* add additional emit keywords
* update solidity-coverage to 0.4.15
* update to solium 1.1.6
* fix MerkleProof coverage analysis by testing through wrapper
* change version pragma to ^0.4.21
* fix solium linting errors
