Ability to receive an email notification for the next game [3]

A few players have asked for the option to get an email each day.

* Add UI on the tombstone to enter email.
* Send verification email.
* Add to database with user's timezone.
* Log user in on their return.
* Run background task each hour which checks for users who want an email.
* Detect if that player has played already that day.
* Send email if not.
* Option to unsubscribe in the email.