Cherry-pick from #200 - update the function signature - format code-style - move _compile into separate functions - fix a bug in to_torch and to_numpy (Batch) - remove None in action_range In short, the code-format only contains function-signature style and `'` -> `"`. (pick up from [black](https://github.com/psf/black))
Bipedal-Hardcore-SAC
- Our default choice: remove the done flag penalty, will soon converge to ~270 reward within 100 epochs (10M env steps, 3~4 hours, see the image below)
- If the done penalty is not removed, it converges much slower than before, about 200 epochs (20M env steps) to reach the same performance (~200 reward)