Cleaned up repo and added Travis CI integration

- Added Travis CI integration
- Updated README
  - Updated download instructions
  - Added contribution instructions
- Renamed src and diet files to backfire.js
- Updated name in READMe to BackFire (used to be Backfire) to be
consistent with other bindings
- Cleaned up package.json
- Cleaned up bower.json
- Added change log
- Made it so that tests can be run via “grunt test”
- Added release.sh script to streamline release process
- Updated karma configuration file
Updated README and release.sh script
Fixed typos in README
Merge pull request #72 from firebase/repo_cleanup

Cleaned up repo and added Travis CI integration