Remove fucking test enumeration from globaleaks.tests.jobs.test_cleaning_sched.
A more appropriate handling of strings in base_updater.

* Change base_updater to use twisted log instead of shitty prints all around the
  code.
* Add mock as test dependency (it is a backport of python3's stdlib mock, dudes,
  do not harass me with this dependency)
* Patch stdout not to pollute unittests output.