Fix method any_moves? in King, Pawn, Knight and Piece and ChessBoard#any_moves_for_player_on_turn?
Test checkmate
Add a new checkmate test
Fix typo in King#castle?
Add a new test
Fix bug in Piece#any_moves?
Add one more test
Test if black win
Add another test
Add a test
Add another test
Fix a bug in King#castle?
Add test with castling