Added email notifications for closing a game

To test:
1. Close an open game.
2. Check the console for Janeway - there should be output that the email was sent, and the addresses it was sent to.
3. Check mailtrap to check the text of the email.

The email and password for Mailtrap are struct.by.lightning@gmail.com and team6password.

Committed by: Alec Thompson - ajthompson