Friends System

[thedustinsmith]

This is more @alsmpd 's idea, but we could implement a friends system.

To start off with (while we're using firebase) it might be easiest just to store a friends [ ] on the user that contains a list of userids.

Features this would make possible:

1. When creating a game - select the friends that are in the game. Maybe they don't even have to join, just automatically are in the game.
2. Send Invites to games to friends.

This gives me another idea. You could use this friend functionality to schedule a game. Say I wanted to play a round this Friday. I could create the game, and add my friends to it. Then my friends would see the game and maybe get notifications, etc. Just spitballing now.