fixed OpenAI fetch tasks; added nicer imports

alr_envs/dmc/suite/ball_in_cup/__init__.py

@@ -0,0 +1 @@
+from .mp_wrapper import MPWrapper

alr_envs/dmc/suite/ball_in_cup/mp_wrapper.py

@@ -2,10 +2,10 @@ from typing import Tuple, Union
 
 import numpy as np
 
-from mp_env_api.interface_wrappers.mp_env_wrapper import MPEnvWrapper
+from mp_env_api import MPEnvWrapper
 
 
-class DMCBallInCupMPWrapper(MPEnvWrapper):
+class MPWrapper(MPEnvWrapper):
 
     @property
     def active_obs(self):