Added goal_pos variable to MultiRoomEnv

gym_minigrid/envs/multiroom.py

@@ -112,7 +112,7 @@ class MultiRoomEnv(MiniGridEnv):
         self.place_agent(roomList[0].top, roomList[0].size)
 
         # Place the final goal in the last room
-        self.place_obj(Goal(), roomList[-1].top, roomList[-1].size)
+        self.goal_pos = self.place_obj(Goal(), roomList[-1].top, roomList[-1].size)
 
         self.mission = 'traverse the rooms to get to the goal'