Fix number of players for KoiKoi game to 2 on the type level

src/Hanafuda/KoiKoi.hs

@@ -49,8 +49,8 @@ play move game@(Game {river, step}) =
   where
     canCatch card1 card2 = flower card1 == flower card2 && river `contains` card2
 
-new :: MonadIO m => [PlayerID] -> Mode -> m Game
-new playersList mode = do
+new :: MonadIO m => (PlayerID, PlayerID) -> Mode -> m Game
+new (playerA, playerB) mode = do
   playing <- Player.random players
   Round.deal $ Game {
         mode
@@ -67,4 +67,4 @@ new playersList mode = do
       , rounds = []
     }
   where
-    players = Player.players playersList
+    players = Player.players [playerA, playerB]