Merge branch 'master' into peer-dep

contracts/drafts/ERC1046/TokenMetadata.sol

@@ -12,6 +12,8 @@ import "../../token/ERC20/IERC20.sol";
  */
 contract ERC20TokenMetadata is Initializable, IERC20 {
   function tokenURI() external view returns (string);
+
+  uint256[50] private ______gap;
 }
 
 
@@ -28,4 +30,6 @@ contract ERC20WithMetadata is Initializable, ERC20TokenMetadata {
   function tokenURI() external view returns (string) {
     return _tokenURI;
   }
+
+  uint256[50] private ______gap;
 }

contracts/drafts/ERC20Migrator.sol

@@ -99,4 +99,6 @@ contract ERC20Migrator is Initializable {
     uint256 amount = Math.min(balance, allowance);
     migrate(account, amount);
   }
+
+  uint256[50] private ______gap;
 }

contracts/drafts/SignatureBouncer.sol

@@ -140,4 +140,6 @@ contract SignatureBouncer is Initializable, SignerRole {
 
     return signer != address(0) && isSigner(signer);
   }
+
+  uint256[50] private ______gap;
 }

contracts/drafts/TokenVesting.sol

@@ -176,4 +176,6 @@ contract TokenVesting is Initializable, Ownable {
       return totalBalance.mul(block.timestamp.sub(_start)).div(_duration);
     }
   }
+
+  uint256[50] private ______gap;
 }