Comment (by Steven R. Brandt):

OK, I've pushed a new version of the Dockerfile. It uses 16.04 because if I use a later version, then I can't run the image in singularity on older machines. I've put this and other justifications for my choices of packages in the Dockerfile.

--
Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2234/trouble-in-the-tutorial-server