Miscellaneous repo cleanup

- Cleaned up package.json
- Cleaned up bower.json
- Cleaned up wording, fixed broken links, and improved contribution
instructions in README.md
- Removed grunt-cli as a dependency in .travis.yml
That's a fair point. I think we can look to do this in the future. Our official docs are probably a better introduction anyway. As you mentioned in your email, this may become a moot point once this repo get merged into the Firebase client.