Two things:
1. I've never attempted to support this before.
2. It seems surprisingly and perhaps deceptively simpler than what I
expected. I'm unsure what to do once Google's API authenticates the user. I
currently look-up the user's role, trips, etc. using their email address. The
role is stored in the Accounts table alongside username, email, password. I
will speak with the interviewer tomorrow about this.