update mujoco and tensorflow 1.14/2.0 api calls in efficient-hrl (#6525)

* updated mujoco api calls to data, and tensorflow call to CriticalSection (moved from contrib.framework)

* changed efficient-hrl envs so self.physics points to correct PyMj object based on mujoco_py version

* corrected mujoco version number checkm in AntEnv.physics and PointEnv.physics properties

* fix AntEnv.set_xy by reverting to using self.physics