clippy + cleanup

src/game.rs

@@ -1,4 +1,8 @@
-use crate::{agent::Agent, board::Board, piece::Piece};
+use crate::{
+    agent::Agent,
+    board::{Board, Winner},
+    piece::Piece,
+};
 
 pub struct Game {
     players: [Box<dyn Agent>; 2],
@@ -93,15 +97,15 @@ impl Game {
             println!("{}", self);
 
             match self.board.game_winner(self.players[current_player].color()) {
-                crate::board::Winner::Player(piece) => {
+                Winner::Player(piece) => {
                     println!("{} Wins!", piece.text());
                     break;
                 }
-                crate::board::Winner::Tie => {
+                Winner::Tie => {
                     println!("Game Tied!");
                     break;
                 }
-                crate::board::Winner::None => {}
+                Winner::None => {}
             }
 
             self.step(current_player);