[3dprinting] PR review request: Update Printrun to 2.x with Python 3

Anyone available to review this Pull Request? https://src.fedoraproject.org/rpms/printrun/pull-request/2 (I want to push this to F28. It's a Release Candidate version, but I will backport all fixes, we need to get this to boarder audience.) Thanks, -- Miro Hrončok -- Phone: +420777974800 IRC: mhroncok