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).
This is splitting hairs, but technically should the Player know how to create a new board?  Maybe you should instantiate @board inside of the ToH class rather than the Player class