Add workflow content
Finish revising existing resources
Fix Zookeeper docker command
Use Zooniverse Zookeeper
Add SetMemberSubject Group
Pluralize types
Fix apiary reported errors
Add % to signed url regex

Closes #280
Merge pull request #281 from edpaget/fix-brittle-url-spec

Add % to signed url regex
Merge pull request #279 from edpaget/workflow-content-apiary

Workflow content apiary
Merge pull request #278 from edpaget/zk-readme-fix

Fix Zookeeper docker command