Fix linting errors and warnings

contracts/asset-proxy/contracts/src/ERC1155Proxy.sol

@@ -28,6 +28,7 @@ contract ERC1155Proxy is
     // Id of this proxy.
     bytes4 constant internal PROXY_ID = bytes4(keccak256("ERC1155Assets(address,uint256[],uint256[],bytes)"));
 
+    // solhint-disable-next-line payable-fallback
     function () 
         external
     {

contracts/asset-proxy/contracts/src/libs/LibAssetData.sol

@@ -448,10 +448,12 @@ contract LibAssetData is
             "WRONG_PROXY_ID"
         );
 
+        // solhint-disable indent
         (amounts, nestedAssetData) = abi.decode(
             assetData.slice(4, assetData.length),
             (uint256[], bytes[])
         );
+        // solhint-enable indent
     }
 
     /// @dev Calls `token.ownerOf(tokenId)`, but returns a null owner instead of reverting on an unowned token.

contracts/extensions/contracts/src/DevUtils/DevUtils.sol

@@ -23,6 +23,7 @@ import "./OrderValidationUtils.sol";
 import "@0x/contracts-exchange-libs/contracts/src/LibTransactionDecoder.sol";
 
 
+// solhint-disable no-empty-blocks
 contract DevUtils is
     OrderValidationUtils,
     LibTransactionDecoder