orchestrator: Add test debugging
orchestrator: Add test debugging

TestUpdaterRollbackAndPauseNoMonitor fails sometimes. After tens of
thousands of repetitions, I can't reproduce the failure locally. This
adds some debugging to capture information about the failure.

Signed-off-by: Aaron Lehmann <8ecfc6017a87905413dcd7d63696a2a4c351b604@docker.com>

Noyan759/swarmkit,dperny/swarmkit-1,Noyan759/swarmkit,AliyunContainerService/swarmkit,docker/swarmkit,jlhawn/swarmkit,RenaudWasTaken/swarmkit,AliyunContainerService/swarmkit,docker/swarmkit,jlhawn/swarmkit,diogomonica/swarmkit,cheyang/swarmkit,dperny/swarmkit-1,sungwonh/swarmkit,cheyang/swarmkit,sungwonh/swarmkit,diogomonica/swarmkit,RenaudWasTaken/swarmkit,alyyousuf7/swarmkit,alyyousuf7/swarmkit