Move tincan to the openedx fork #464
Description
We rely heavily on the tincan package for our xAPI transformations, however it hasn't been updated in 4 yrs. Openedx already has a fork of this that is being used in edx-platform: https://github.com/openedx/TinCanPython it's likely that this is the version that ERB is actually picking up when running in that environment, so that's what we should test with here.
We should also update that fork to our own current standards if we're going to maintain it!