Resolving breaking changes leading up to Gym 1.0

[ryanrudes]

Gym 1.0, according to the developers' roadmap, will introduce a number of breaking changes and deprecations that will necessitate appropriate changes to colabgymrender. The ones of concern are mainly:

• Updated render API requires render mode to be provided at environment initialization, rather than on step()
• Updated step API will soon return 5 outputs, that is, observation, reward, terminal, truncation, info
• Updated reset will always return info now, in addition to observation

As of right now, the plan for colabgymrender is to play along with these new changes by incrementing the major version of this package to avoid any strange surprises. We'll probably introduce colabgymrender==2.0.0 around the same time gym introduces its first major version.

Feel free to discuss your opinion on this roadmap below. #