ARGO-279: fix workflow_should_show_completed? to return true when all steps have a status of 'skipped', 'completed', empty string, or nil.  fix relevant test to correctly exercise new behavior, fix old test that depends on slightly altered shared test setup, fix spacing in shared test setup.
Merge pull request #24 from sul-dlss/workflow_status_to_solr_ARGO-279_pt2

ARGO-279: fix workflow_should_show_completed?
Fixing merge conflicts
Version bump to 4.15.2