Get WorkItemPersist passing.

@macumber after verifying that the test has failed in the same manner
since it was originally created, I updated this test to be an end-to-end
test of persisting a workflow, loading the workflow, creating a job tree
from the workflow and creating a workflow from the job tree, to verify
that data is workflow key is maintainted through all aspects of the
lifecycle.
Merge branch 'develop' of https://github.com/NREL/OpenStudio into develop