Add support for RAIB reports

This PR contains the work in specialist-publisher for editors from the
"Rail Accident Investigation Branch" to publish reports. It contains:

 - the schema of the possible values of the facets in the RAIB Report
   form
 - the models, services, observers, repo and views for RAIB reports
 - adding RAIB editors to permission checker
 - testing RAIB Report workflow
Also, this isn't meant to match the name. The permission checker is checking the slug of the Org, nothing more. It doesn't matter what we think it's called, we have to match whatever is coming from Sign On.