Beefed up release script
Beefed up release script

- Ensures change log has been updated for the to-be-released version
- Ensures package.json has the correct version number
- Ensures bower.json has the correct version number
- Checks if the git tag has been created without having to ask the user

googlearchive/firebase-simple-login,rawrsome/firebase-simple-login,googlearchive/firebase-simple-login,rawrsome/firebase-simple-login