Remove "slave" field from jenkins

I can't easily get the hostname from the plugin infrastructure, from
what I can see, so I am going to remove these fields for now.
Test tagger rank change messages.  Fixes #14.
First work on the ElectionsProcessor for fedora-elections
Update the elections Processor now that the messages contain an agent
Adjust the __link__ now that the elections is on apps
Manage messages regarding elections' candidate (new, edit, delete)
Adjust the setup.py file to include the elections processor
Import the ElectionsProcessor from the right file
Fix trailing slash in the link in the elections processor and make it valid python
Fix the usernames method

We never broadcast the `fas_user` attribute so no need to account
for it.
Cover the case where there would be no `agent` define (cf what fedocal
does)
pep8 fixes to the fedocal tests
Fix the name, messages from the elections are of type fedora_elections
Fix the topic for editing or deleting candidates (and not elections)
The messages are only broadcasting one candidate at a time, no list
Add unit-tests for the fedora_elections messages
Link the unit-tests for fedora_elections into the main test suite
pep8 fixes on the trac tests
pep8 fixes on the summershum tests
pep8 fixes on the mailman3 tests
pep8 fixes on the pkgdb tests