Fix Review Bot when running against Review Board 3.0.8+
Review Request #10080 — Created July 13, 2018 and submitted
In Review Board 3.0.8, we split all the auth backends into their own
modules. This works in most cases, but Review Bot manually assigns a
backend path when creating the session key. This failed because that
path is used to index into a dict of loaded backends within the django
This fix adds a manual version check to ensure we set the correct auth
backend path for each version.
Was able to properly detect the worker nodes.