Pull Request now includes Tetris!

completed: warmups
tower of Hanoi (with saving via YAML)
Mastermind(no saving, but yes AI)

Single block Tetris, with high scores saved, plus a difficulty setting as well. (Boring under about level 8).
The part where you define what the possible range of letters are should probably be a part of the Board class, rather than Player class for super duper OOPiness