Switching everything to ElasticSearch.

In the few cases that I cannot switch things I have made it clear why not, and renamed the old content api so that nobody uses it for new queries.
New test data files
Merge branch 'master' of github.com:guardian/frontend into elastic-content-api
Merge branch 'master' of github.com:guardian/frontend into elastic-content-api
Merge branch 'master' of github.com:guardian/frontend into elastic-content-api
Seriously :)
UsesElasticSearch is no longer needed
Merge branch 'master' of github.com:guardian/frontend into elastic-content-api
Merge branch 'master' of github.com:guardian/frontend into elastic-content-api
Merge pull request #3148 from guardian/elastic-content-api

Switching everything to Elastic Search content api.