Add partner enquiry processor stub

No tests at the moment, some will be added in member-directory, and some here later.
Add offer_category for the membership level they're interested in.
Merge branch 'refs/heads/master' into feature-150-partner-enquiry

Conflicts:
	lib/open-orgn-services.rb
break apart hash to fit schema.org objects
Merge branch 'refs/heads/master' into feature-150-partner-enquiry

Conflicts:
	lib/open-orgn-services.rb
Merge pull request #151 from theodi/feature-150-partner-enquiry

Add partner enquiry processor stub