separated computer from board dependency

Initialy the game was set up to call for a computer and a player.
I've changed the semantics so that it accounts for two players. I can
pass an instance of computer in as a player, but it is not required. All
string are severed from the computer class in order to play the game.
update SpecRunner to include all models

Initially I was testing specs one at a time based on class so I wouldn't
have to folder hop back and forth to remedy errors in order from the
rewrite.

It could have been done but I prefered handling one class at a time.
Merge pull request #24 from zachmokahn/touch_up_board_and_computer

Touch up board and computer