Add slug to Repository, for api & index id creation
Merge branch 'master' into dpla_harvester
Add to Collection  - url_harvest, harvest_extra_data and harvest_type.

Drop oai_set_spec, more uniform data access for harvester.
Add enrichments_item for prospective specifying of enrich process
chains.
Add url_harvest filter to admin.
Now just pass user email & api url when starting harvest.

Makes the command line parsing much easier and can be more easily
distributed.
Add OAJ type of harvest (JSON interface, deprecated)

The OAC type will now be from xml feed.
Add arks to campus

pivotal story: https://www.pivotaltracker.com/story/show/69946804
Add check of campus ark.
Add check of duplicate ark for campus.
Fix check of campus arks for blank ark.
Add check for duplicate ark for repository in save