Add functionality to leave and retire room

Add functionality to leave and retire room

docstring
Update CreateGame to use authentication and existing data from rooms
Update README.md
Update SinkBall to take advantage of auth
Allow signup through client
Make player info returned more relevant
Salt and hash passwords
Update README.md

Update README.md

Update README.md
Move client.py into own folder

Remove TODO

Move client.py into own folder

Update README.md