Add Feature#end! method to end a feature
Fixup Feature <-> Document association

Editions have never directly been associated with Features
Update gem to latest toolkit and include new _measurements.scss
Show transition progress for non ministerial orgs

 - Remove show_govuk_status from non-ministerial orgs when
   progress bar is shown.
 - Change text from "n agencies on GOV.UK" to "n on GOV.UK"

https://www.pivotaltracker.com/s/projects/367813/stories/60673236
Unpublishing an edition also unfeatures it.

Prior to this, unpublished documents were still being featured on
organisations and world locations. This was causing 500s on front-end.
Merge pull request #1039 from alphagov/update-gem-to-latest-toolkit

Update gem to latest toolkit and include new _measurements.scss
Merge pull request #1047 from alphagov/60673236-non-ministerial-department-transition-progress-bar

Show transition progress for non ministerial orgs

https://www.pivotaltracker.com/s/projects/367813/stories/60673236
Merge pull request #1044 from alphagov/50033335-unpublishing-removes-featurings

Unpublishing removes featurings