matplotlib isn't in requirements.txt

[danbri]

I needed to pip install matplotlib for the simple_es_example.ipynb demo to work; should it be in requirements.txt?

[danbri]

hmm but then neither is box2d-py, which I needed to run estool$ python train.py rocketlander -n 8 -t 4, which makes me suspect I don't understand quite the purpose of requirements.txt. Also I needed to comment out the estool==1.0 line to run this stuff from the github-cloned directory.