added created field to users api
get workgroups by course
Merge pull request #112 from edx-solutions/ziafazal/add-created-field-to-user-serializer

added created field to users api
Merge pull request #118 from edx-solutions/ziafazal/get-workgroups-by-course

get workgroups by course
drag-and-drop-v2: Add new XBlock
mattdrayer/api-currentcontentid: GET response now returns content position_tree
Merge pull request #105 from edx-solutions/mattdrayer/api-currentcontentid

mattdrayer/api-currentcontentid: GET response returns current content identifier
drag-n-drop-v2: Update hash
drag-and-drop-v2: Update hash
Initial setup of sessions doc
Sessions api doc initial setup
edits
Sessions edits