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).
you could do away with the dictionary array altogether here and just run

`file.each_line do |entry_word|`
...
and it'd do the same thing