Link firebase authentication with custom nodejs authentication. #18
Description
Right now, when you log in with firebase, it sends a request to the backend server, which checks the uid using the firebase admin API to determine if the person is logged in or not. We need to use this endpoint to generate an entry in the auth table with a UUID for the user, and return an auth token. At this point, we should also store the link between the phone number (retrieved via admin API) and the UUID we give them (should check this table first to see if it is a new account, or re-authentication attempt)