Added load and save to env (left GridTransitionMap load and save for now)

https://pep8.readthedocs.io/en/latest/intro.html#error-codes

loads a pre-saved model from Nets (not sure if working)
added some frame, time, episode text info to RenderEnv (still in matplotlib)
added some flake8 ignores to tox.ini - mostly hanging index-related.

Also changed a line to be 86 chars long in rendertools.py