Add more verbose logging to temporaryjob
Got rid of some dependency
[agent] fix pull code

Now instead of pulling and then failing if pull fails, only fail
if we don't have the image after the pull attempt.  This way, if
you're using a locally built docker image, while we'll try to pull
it, when the pull inevitably fails, the agent will see that the
image is there and continue anyway.
Merge pull request #90 from spotify/tmpjob_log

Add logging to TemporaryJob{s}
Merge pull request #92 from spotify/drewc/pullfix

[agent] fix pull code
TemporaryJobs now sets randomized registration domain

When helios registers a service in DNS, it will insert this random string into
SRV record. This is so multiple tests can run concurrently, without having
them clobber each other's DNS records.