Add update job scheduling and reporting
    
    Summary:
    This adds a `jobs_from_update` function to schedule jobs for a
    specified Bodhi update, a CLI subcommand for doing this, and
    adjusts the scheduling fedmsg consumer to do it automatically
    whenever a critpath update is created (technically, whenever a
    push to 'testing' is requested, but that's almost always on
    creation) or edited. It also adjusts the reporting code to
    handle update test jobs: the consumer and CLI code do not need
    adjustment. We can tweak this in future to run the tests for
    updates with particular packages or whatever, just running for
    every critpath update seems like a good place to start. I
    specifically didn't get any smarter about only running the tests
    if the edit changed the packages because it lets us say 'if you
    want the tests to be re-run, just edit the update'.
    
    Test Plan:
    The test suite was extended, so check that :) Also,
    try scheduling jobs via the CLI, and if you can, by using the
    testing consumer and replaying appropriate fedmsgs (or just
    turning on the prod consumer, pointing it at your openQA
    instance and waiting...). Try reporting an update job result
    to a local test instance of ResultsDB using the CLI. Note:
    you need the very latest resultsdb_conventions release (so use
    git master or grab the package from Koji).
    
    Reviewers: jsedlak
    
    Reviewed By: jsedlak
    
    Subscribers: tflink
    
    Differential Revision: https://phab.qa.fedoraproject.org/D1152