Archive published editions for docs with more than 1 published edition

There's a data migration to do it this this, but it uses some new code in data_hygiene/extra_published_editions_repairer so we can run it again later.  Lets face it, we're likely to need to.
Merge pull request #557 from alphagov/fix-extra-published-editions

Archive published editions for docs with more than 1 published edition

https://www.pivotaltracker.com/story/show/49876401