Removed BreakInvariantBounty. (#1424)

(cherry picked from commit 9be0f100c4)

contracts/drafts/BreakInvariantBounty.sol

@@ -1,93 +0,0 @@
-pragma solidity ^0.4.24;
-
-import "../payment/PullPayment.sol";
-import "../ownership/Ownable.sol";
-
-/**
- * @title BreakInvariantBounty
- * @dev This bounty will pay out to a researcher if they break invariant logic of the contract.
- */
-contract BreakInvariantBounty is PullPayment, Ownable {
-  bool private _claimable;
-  mapping(address => address) private _researchers;
-
-  event TargetCreated(address createdAddress);
-  event BountyCanceled();
-
-  constructor() public {
-    _claimable = true;
-  }
-
-  /**
-   * @dev Fallback function allowing the contract to receive funds, if they haven't already been claimed.
-   */
-  function() external payable {
-    require(_claimable);
-  }
-
-  /**
-   * @dev Determine if the bounty is claimable.
-   * @return false if the bounty was claimed, true otherwise.
-   */
-  function claimable() public view returns(bool) {
-    return _claimable;
-  }
-
-  /**
-   * @dev Create and deploy the target contract (extension of Target contract), and sets the
-   * msg.sender as a researcher
-   * @return A target contract
-   */
-  function createTarget() public returns(Target) {
-    Target target = Target(_deployContract());
-    _researchers[target] = msg.sender;
-    emit TargetCreated(target);
-    return target;
-  }
-
-  /**
-   * @dev Transfers the contract funds to the researcher that proved the contract is broken.
-   * @param target contract
-   */
-  function claim(Target target) public {
-    require(_claimable);
-    address researcher = _researchers[target];
-    require(researcher != address(0));
-    // Check Target contract invariants
-    require(!target.checkInvariant());
-    _asyncTransfer(researcher, address(this).balance);
-    _claimable = false;
-  }
-
-  /**
-   * @dev Cancels the bounty and transfers all funds to the owner
-   */
-  function cancelBounty() public onlyOwner{
-    require(_claimable);
-    _asyncTransfer(owner(), address(this).balance);
-    _claimable = false;
-    emit BountyCanceled();
-  }
-
-  /**
-   * @dev Internal function to deploy the target contract.
-   * @return A target contract address
-   */
-  function _deployContract() internal returns(address);
-
-}
-
-/**
- * @title Target
- * @dev Your main contract should inherit from this class and implement the checkInvariant method.
- */
-contract Target {
-
-   /**
-    * @dev Checks all values a contract assumes to be true all the time. If this function returns
-    * false, the contract is broken in some way and is in an inconsistent state.
-    * In order to win the bounty, security researchers will try to cause this broken state.
-    * @return True if all invariant values are correct, false otherwise.
-    */
-  function checkInvariant() public returns(bool);
-}

contracts/mocks/BreakInvariantBountyMock.sol

@@ -1,29 +0,0 @@
-pragma solidity ^0.4.24;
-
-// When this line is split, truffle parsing fails.
-// See: https://github.com/ethereum/solidity/issues/4871
-// solium-disable-next-line max-len
-import {BreakInvariantBounty, Target} from "../drafts/BreakInvariantBounty.sol";
-
-
-contract TargetMock is Target {
-  bool private exploited;
-
-  function exploitVulnerability() public {
-    exploited = true;
-  }
-
-  function checkInvariant() public returns (bool) {
-    if (exploited) {
-      return false;
-    }
-
-    return true;
-  }
-}
-
-contract BreakInvariantBountyMock is BreakInvariantBounty {
-  function _deployContract() internal returns (address) {
-    return new TargetMock();
-  }
-}