Merge tag 'v2.1.1' of github.com:OpenZeppelin/openzeppelin-solidity

v2.1.1

contracts/mocks/SignerRoleMock.sol

@@ -1,8 +1,7 @@
-pragma solidity ^0.4.24;
+pragma solidity ^0.5.0;
 
 import "../access/roles/SignerRole.sol";
 
-
 contract SignerRoleMock is SignerRole {
     constructor() public {
         SignerRole.initialize(msg.sender);
@@ -13,6 +12,7 @@ contract SignerRoleMock is SignerRole {
     }
 
     function onlySignerMock() public view onlySigner {
+        // solhint-disable-previous-line no-empty-blocks
     }
 
     // Causes a compilation error if super._removeSigner is not internal