Release Improvements

This epic is a draft at the moment.

Vaguely formulated goal:

• Automatic daily/nightly production composes
• the t_functional test suite gets run on every production compose, results publicly visible, clear guidelines on how to contribute tests
• publishing kept once a week, by promoting an existing production compose after it has tests passed

Question to answer:

• where do we run the tests? They can get triggered by our Jenkins, but they need to run somewhere.

Some other ideas:
We might want to emit fedmsg messages for various things.
We might want issues to be filed for Watcher Duty on compose test failures.