Add spaces after comment blocks for flake8 compliance.
Remove QueensideRook and KingsideRook in favor of Rook (distinction won't be important).
Remove imports of QueensideRook and KingsideRook. Refactor Rook tests. Tests pass.
Fix comment. Replace explicit args in method call.
Fix formatting for clarity.
Begin to write skeleton of set_actual_moves_cache.
Add @abstractmethod decorator to Piece's generate_naive_cache.