[v3] Auth Module: Bring methods in-line & add missing methods #118

Currently working through the auth docs on my own fork, there's some differences between the Firestack methods vs the JS method names. I believe it should mimic the Firebase API as close as possible, since most users will reference their docs on how to do certain things, it'd make it easy to come straight to the same method here.

Also some methods are missing:

Differences:

• listenForAuth
  • onAuthStateChanged
  • Might also be worth renaming unlistenForAuth to removeOnAuthStateChanged or something?
• createUserWithEmail
  • createUserWithEmailAndPassword
• signInWithEmail
  • signInWithEmailAndPassword
• updateUserEmail
  • updateEmail
• updateUserPassword
  • updatePassword
• updateUserProfile
  • updateProfile
• sendPasswordResetWithEmail
  • sendPasswordResetEmail
• deleteUser
  • This is just user.delete(), not sure whether firebase.auth.delete() would feel correct?

Missing:

• sendEmailVerification ([v3] sendEmailVerification is not supported #114)

Not working

• signOut
  • Returns ok but doesn't sign out.
• signIn with disabled account(all?)
  • Crashes the app on boot.