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
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