unblocking the py3 transition

Hi everyone, The transition to python3-only is blocked on three missing python packages in EPEL7: - python36-werkzeug: tracked by https://bugzilla.redhat.com/show_bug.cgi?id=1545888 - python36-pecan: tracked by https://bugzilla.redhat.com/show_bug.cgi?id=1766839 - python36-cherrypy: tracked by https://bugzilla.redhat.com/show_bug.cgi?id=1765032 In order to get these into EPEL, they need to go into Fedora first, which has its own (slow) process. In the meantime, these packages are easy to build manually as one-offs (and may already have been built by David and sitting in a temporary repo). To unblock this, what if we require that temporary repo for centos7 *master* installs, and add it to the teuthology workers via ceph-cm-ansible? The assumption is that by the time we release octopus we will have gotten the dependencies in to the appropriate upstream repos. That means we have until March 2020... 4 months away. Thanks! sage