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).
Ditto on that, but it's actually a super tricky problem to figure out.  I didn't get it right in every edge case in my game either.  Here's a sample (The code is AAAC):

Guess #1: AAAA   |  RRRW
Guess #3: CCCC   |  WWWR