Announce current assignments on startup of agent

Previously, the agent would only announce those during its regular
reannounces.
Merge pull request #87 from guidow/announce_assignments_on_startup

Announce current assignments on startup of agent
expectations fix
remove unused imports
provide a reason for the skip in @skip_on_ci
fixing DeprecationWarning
removing unused imports
Merge pull request #88 from pyfarm/unittest_fixes

Unittest fixes
Merge branch 'master' of github.com:pyfarm/pyfarm-agent into jobtype_rework