Fix: Did not define MP_Wrapper for new RandomInit version of BoxPushing

fancy_gym/envs/__init__.py

@@ -215,6 +215,7 @@ for reward_type in ["Dense", "TemporalSparse", "TemporalSpatialSparse"]:
     register(
         id='fancy/BoxPushingRandomInit{}-v0'.format(reward_type),
         entry_point='fancy_gym.envs.mujoco:BoxPushing{}'.format(reward_type),
+        mp_wrapper=mujoco.box_pushing.MPWrapper,
         max_episode_steps=MAX_EPISODE_STEPS_BOX_PUSHING,
         kwargs={"random_init": True}
     )