gym version will affect the usage of ray[rllib] about macad-gym

[Morphlng]

There are also a bunch of incompatible api usage in the code should be noted. For example, some _private_attribute (e.g. Box._shape) is no longer accessible. User should whether stick with gym==0.12.6 or we would have to do a lot of job to handle these problems.

[praveen-palanisamy]

Thanks for identifying this and posting with details! Like you pointed out, the OpenAI Gym library started wrapping the env with the OrderEnforcing wrapper to ensure the env throws an error if env.step(...) is called before an initial env.reset().
For users using latest version of gym (gym>=0.21.0) with ray[rllib], current workaround is to replace env with env.wrapped in the user's code. This workaround is needed not just with MACAD-Gym environments but likely with any MultiAgent Gym environment with a wrapper class. The ray[rllib] team has decided not to support Gym wrappers in their MultiAgent Env implementation.