Closes #ISSUE
More accurately map localhost to `127.0.0.1`. Previously we would
lowercase and simply replace all instances of localhost inside of the
URL string, meaning query parameters, username, password etc. could not
contain the string `localhost` or contain uppercase letters without
getting modified. Added a test ensuring the mapping logic works. The
previous implementation would fail this new test.
Release Notes:
- Improved the behavior of mapping `localhost` to `127.0.0.1` when
passing configured proxy urls to `node`
ba7ea71c00