Removed BreakInvariantBounty.

contracts/mocks/BreakInvariantBountyMock.sol

@@ -1,33 +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 {
-  constructor() public {
-    BreakInvariantBounty.initialize(msg.sender);
-  }
-
-  function _deployContract() internal returns (address) {
-    return new TargetMock();
-  }
-}