Get rid of the Brandon Rook test code
Remove "turn" and "turn_number" from valid_moves()
Implement the rook using a pure function
Remove the old Rook class
Remove Queen and Bishop classes
Factor out can_move_to() from go()
Replace Knight with a function
Replace King class with a function
Replace Pawn with a function
Remove BoardSquare.py
Remove old ChessPieces.py
Remove old "test.py"
Add simple PyGame example
Add simple Flask-powered web app
Merge pull request #10 from brandon-rhodes/master

March 6th work