Refactor _Job out, fix a few failing tests
Add tests for _Job, fix some _Job bugs
Remove unused import
Add docstring for job start
Move CheckFailure to test utils, so that other tests may check for failure logging
Make job_failed and job_succeeded private, sinnce they are callbacks
Fix docstring and an accidental search and replace
Fix bug with mock modify_state
Merge pull request #275 from rackerlabs/controller-job-refactor

Minor refactor of job logic in the controller
Merge branch 'master' into disallow-update-scheduler-tests