UserTracker is some basic python tooling to monitor certain user activities
within various wikimedia systems (particulary gerrit and phabricator).  For
example, the GerritTracker subclass currently consumes a gerrit API endpoint,
analyzes the data and then emails a report to a mailing list or user, if
necessary.

Bug: T212508
Change-Id: Idcbdfac7f7544d57b4534fee062c46d243d1840c