add RandomAgent

src/main.rs

@@ -1,4 +1,4 @@
-use agent::ManualAgent;
+use agent::{ManualAgent, RandomAgent};
 use complexagent::ComplexAgent;
 use game::Game;
 use piece::Piece;
@@ -14,6 +14,7 @@ fn main() {
     let player1 = ComplexAgent::new(Piece::Black);
     // let player2 = ComplexAgent::new(Piece::White);
     let player2 = ManualAgent::new(Piece::White);
+    // let player2 = RandomAgent::new(Piece::White);
     let mut game = Game::new(Box::new(player1), Box::new(player2));
     game.game_loop();
 }