Upgrading dependencies
Upgrading dependencies

Mostly upgrading to get rid of the Github warning for PyYAML (CVE-2017-18342), but figured I might as well upgrade a few others as well... Gym still needs to be upgraded (see #41).
I did some really basic testing to ensure stuff still runs. No guarantees that I didn't break something subtle though...
bzier/gym-mupen64plus,bzier/gym-mupen64plus