refactor OutputSystem

app/src/main/java/chess/controller/commands/SurrenderCommand.java

@@ -1,7 +1,7 @@
 package chess.controller.commands;
 
 import chess.controller.Command;
-import chess.controller.OutputSystem;
+import chess.controller.event.GameListener;
 import chess.model.Color;
 import chess.model.Game;
 
@@ -14,7 +14,7 @@ public class SurrenderCommand extends Command {
 	}
 
 	@Override
-	public CommandResult execute(Game game, OutputSystem outputSystem) {
+	public CommandResult execute(Game game, GameListener outputSystem) {
 		outputSystem.hasSurrendered(player);
 		outputSystem.winnerIs(Color.getEnemy(player));
 		return CommandResult.NotMoved;