[WIP] Atari part2

[JulienT01]

Description

Update rlberry to manage vectorized Atari env. (training on many environment).

So far, It's not crashing, but all the training tests failed....
Need to find why...

Checklist

• My code follows the style guideline
  To check :
  black --check examples rlberry *py
  flake8 --select F401,F405,D410,D411,D412 --exclude=rlberry/check_packages.py --per-file-ignores="init.py:F401"
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have set the label "ready for review" and the checks are all green