Merge pull request #1 from dminor/master

Additional unit tests for jobs.
Add first cut of stresstest script
Merge branch 'stresstest'
Return a 404 response from /claim when no jobs are available
Merge pull request #3 from luser/claim-404

Return a 404 response from /claim when no jobs are available
Error when running server without a database present.
Merge latest taskcluster.