Merge pull request #76 from alphagov/add-manuals

Add manuals
Temporary hack to reomve CMA fields from Manual Docs
File attachments for manual documents
Moved assocation marshaller and added specs
Merge pull request #78 from alphagov/manual-documents

Manual documents

https://trello.com/c/CIVqY1uh/63-manuals-add-document-to-a-manual-5
Remove deprecated SpecialistDocumentRepository#store!
Merge pull request #79 from alphagov/remove-store-bang

Remove deprecated SpecialistDocumentRepository#store!
Arrayify manual documents before mapping

Existing manuals won't have a documents attribute yet. Rather than set
documents on all existing data we just arrayify the input to turn nil
into an empty array.
Merge pull request #80 from alphagov/fix-nil-documents-bug

Arrayify manual documents before mapping
Temporary hack to reomve CMA fields from Manual Docs
Moved assocation marshaller and added specs
Missing require for document association marshall
Swap manuals and documents position in navigation
Access control feature test
Fix test authentication and external service stubbing
Only show documents link if user is from CMA

Also redirect the user back to the manuals page and show an error if they
try to visit the documents page directly.
Extract helper method for document permissions
Manuals now have organisation_slug metadata

When creating a manual, the User's organisation_slug is added to the
manual attrs. This is also used to only allow users from the matching
organisation to access their Org's manuals.