Environment variables currently often set as constants or module level variables.

[jangroter]

Environment variables currently often set as constants or module level variables. Because of this it is difficult to initialize an environment properly when calling the environment constructor 'gym.make()'.

Instead it is proposed to clearly specify constants and move all other environment variables into the init() function of their respective variables.

This should then also provide a pathway for providing custom functions for generating observation or action space wrappers later during development.