Remove mailing list mentions

Improve sys-mor demos

While documenting the CI setup in the other PR I discovered
that the "oldest" job actually no longer uses the packages
from the "oldest" pypi mirror. This PR makes sure of that
by removing all installed packages and installing again
from the "oldest" mirror.

Update mailmap before the 2020.2 release

This greatly increases the scope of the test runs on OSX and Windows

fix issue 1193

switch automerge to create merge commits

shader compilation fails on software OGL on headless dockerized osx