Add SetMember counter to SubjectSet #27
Add SubjectCounts concern for Projects and Workflows
Use create instead of build
Use model sum to prevent having to load entire record
Rename subject_count to subjects_count for consistency
Merge pull request #31 from edpaget/feature-subject_counts

Feature subject counts
Update MIME type. Make routes look nice.

This changes the mime-type to be compatible with the JSON API spec. It
also redefines routes closer to what I've been going for with #17.
Use flat api style
Add to_param to ownable
Remove too param method to only use ids for resources
Merge branch 'feature-better_routes'

Conflicts:
	app/models/project.rb