Remove migrations older than 30 days

We don't ever need to run these once all machines that need to apply
them to their database (i.e. production, preview, staging, CI, and
individual developer's boxes) have run them. There's therefore no reason
why we can't just clean them up every now and again.
Sort document series group editions

This matches DocumentSeries#published_editions and causes the order to
be set correctly.
Remove redundant originally_given_at and add location: under doc headings
Move speech location to metadata and add speech type to delivered on

• remove available languges div when empty
• move location from summary to metadata
• add speech_type.name after delivered on
removing if I added around available languages because it breaks 2 tests
add .location class to location to fix failing test
Fix duplication in historic appointment routes

Past foreign secretaries doesn't need to have a constraint in the
regular historic_appointments controller, as it's served entirely as
hard-coded views.

This was originally duplicated in
23636d839e6439114213cba0e446ac551eccc84a.
Monolithic commit re-factors OrganisationType and adds a Devolved Administration type.

• OrganisationType replaced with a static (non-database) model
• OrganisationType related stuff extracted from Organisation into a separate concern.
• OrganisationsController#index cleaned up - all organisations are retrieved with a single query and logic for grouping moved into a new OrganisationsIndexPresenter.
• Lots of updated tests.# This is a combination of 3 commits.
Migration to add new devolved administration organisations.
OrganisationType agency_or_public_body and non_departmental_public_body are now model attributes.
Bring #some# sanity to organisations/index view.
Added devolved administrations to organisations index view.
Validating that devolved administrations are govuk_status exempt.
Resolved merge conflict missed while rebasing.
Trailing new lines
add historic_appointments to application_helper

so chancellors, past prime ministers index and show pages highlight how gov works in the nav
Tidy css and classes for consultation summary

• make open, closed and outcomes use the same classes for styling
• remove unused css after making above change

https://www.pivotaltracker.com/story/show/56783388
Merge pull request #836 from alphagov/document-series-display-order

Sort document series group editions

https://www.pivotaltracker.com/story/show/56704236
Fixed broken test - added a valid devolved_administration factory
Merge pull request #837 from alphagov/move-location-for-speeches-and-add-speech-type

Move location for speeches and add speech type

https://www.pivotaltracker.com/story/show/49530311