zooniverse/Panoptes — pull request #354 by edpaget (2014-12-04 20:10:23+00:00)
Title: Make SubjectSet to Workflow relationship 1 -> *

Remove HABTM relationship between SubjectSet and Workflow so a workflow has
many subject sets and a subject set belongs to a single workflow. This will
support being able to set retirement rules on subject sets.

Closes #148. Closes #338