Google Login & Cloud Saving

I have added the ability to login with your Google account and save your high score to the cloud.

These features were implemented using Cloud Firestore and Firebase Authentication. If you've never seen Firebase in action before, you can rest assured that logging in does not actually give me access to any of your Google information! The only thing that I will be able to see is your basic registration information (your email address, name associated with it) as well as any data stored for the game. (Your high score) By using your Google password to sign in, you are not actually giving me your password but instead sending it through Google's API.