Error importing `matplotlib`

[cemlyn007]

trafficstars

video.py imports matplotlib which is not an explicit dependency listed in setup.py.

Happy to contribute a fix but I do not know which solution do you guys want:

1. Explicitly list the dependency in setup.py - simplest
2. Do not automatically import VideoWrapper from video.py in the wrapper module - this could be argued better if you want a minimal acme dependencies?

Looking forward to hearing from you guys.