fixed OpenAI fetch tasks; added nicer imports

alr_envs/open_ai/mujoco/reacher_v2/__init__.py

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

alr_envs/open_ai/mujoco/reacher_v2/mp_wrapper.py

@@ -0,0 +1,19 @@
+from typing import Union
+
+import numpy as np
+from mp_env_api import MPEnvWrapper
+
+
+class MPWrapper(MPEnvWrapper):
+
+    @property
+    def current_vel(self) -> Union[float, int, np.ndarray]:
+        return self.sim.data.qvel[:2]
+
+    @property
+    def current_pos(self) -> Union[float, int, np.ndarray]:
+        return self.sim.data.qpos[:2]
+
+    @property
+    def dt(self) -> Union[float, int]:
+        return self.env.dt