Firebase Anonymous Authentication

[danieldanielecki]

Adding events will require users to be have an account. The preference would be to use Anonymous Authentication https://rnfirebase.io/auth/usage#anonymous-sign-in & https://firebase.google.com/docs/auth/web/anonymous-auth. Till the moment, we won't have a profile, which isn't expected to be anytime soon; these temporary accounts fit our needs regarding requiring “authentication” in order to add events to the application.