Add skeleton for pieces.
Start adding bishop moves.
Finish bishop moves and add king moves.
Add moves to everything but pawn.
Add pawn class with moves.
Change filename to Pieces.rb
Add board with pieces
Finish move validation
Refactor valid moves
Add unicode graphics for pieces.
Gave back position knowledge to pieces
Can move piece.
Want the squares
Finish all move methods for Piece class
Add check method
Finish checkmate method
Pawns can move two spaces if on initial space