Doesn't work for 'Hopper-v2'

[wsjeon]

I've used the trajectories from the expert's policy in original GAIL code.

Based on trajectories, MuJoCo envs in gym==0.9.0 works well (e.g., Hopper-v1, Walker2d-v1, ...),
but, those envs in gym==0.10.5 (e.g., Hopper-v2).

Thus, I choose to use

• mujoco==0.5.7
• gym==0.9.0
• baselines in my repository which I made a little modification from baselines==0.1.5..