Add Rake task for republishing all current Topical Events
Add Rake task for republishing all current Topical Events

The Topical Event rendering code is currently being moved out of
Whitehall.

Part of this work involves populating the Topical Event content item
with information that is currently missing.

By adding this rake task, we will be able to republish all existing
content items after the `PublishingApi::TopicalEventPresenter` presenter
is updated.

alphagov/whitehall,alphagov/whitehall,alphagov/whitehall,alphagov/whitehall