Corrected some errors in method play

src/game/morpion.cpp

@@ -131,9 +131,9 @@ namespace game
 	void morpion::play(uint16_t m)
 	{   
 		if (current_player() == CROSS)
-			state.cross_bitboard += (1 << m);
+			state.cross_bitboard |= (((uint16_t) 1) << m);
 		else
-			state.circle_bitboard += (1 << m);
+			state.circle_bitboard |= (((uint16_t) 1) << m);
 		
 		//State update
 		state.total_moves++;