Merge branch 'dev-2.1.0' into multiple-stable-coins

Author: VictorVicente

contracts/mocks/PolyTokenFaucet.sol

@@ -18,8 +18,8 @@ contract PolyTokenFaucet {
     mapping(address => uint256) balances;
     mapping(address => mapping(address => uint256)) allowed;
 
-    event Transfer(address indexed _from, address indexed _to, uint256 _value);
-    event Approval(address indexed _owner, address indexed _spender, uint256 _value);
+    event Transfer(address indexed from, address indexed to, uint256 value);
+    event Approval(address indexed owner, address indexed spender, uint256 value);
 
     constructor() public {
         decimals = 18;