Merge pull request #222 from smartcontractkit/update-contracts-1-4-0

Bump @chainlink/contracts to 1.4.0

Author: thodges-gh

contracts/test/MockV3Aggregator.sol

@@ -1,4 +1,4 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
-import "@chainlink/contracts/src/v0.8/tests/MockV3Aggregator.sol";
+import "@chainlink/contracts/src/v0.8/shared/mocks/MockV3Aggregator.sol";