Remove unused SectionEdition scopes
Remove unused SectionEdition scopes

I came across these when trying to upgrade to Rails 4/Mongoid 4 because
Mongoid complained that the scopes weren't wrapped in procs. Having
looked a bit further they don't appear to be used at all so I think we
can safely remove them.

alphagov/manuals-publisher,alphagov/manuals-publisher,alphagov/manuals-publisher