Cleaned up release script and added failed karma reporter

- Lots of clean up to release script. Tried to determine if we would
hit any errors before anything actually happened as much as possible.
Also added more checks for the state of the firepad and
firebase-clients repo to make sure we don’t push unexcited things to
either repo.
- Changed Travis to build the code before running the tests
- Added “failed” reporter to karma to make it easier to tell what tests
failed. It’s only limitation is that asynchronous failures don’t seem
get caught.