Remove combined search endpoints.
Merge pull request #230 from alphagov/remove-combined-search-endpoints

Remove combined search endpoints.
Always add popularity to content indexes

Check if the index is an "auxilary" index, and if not add the popularity
field.  We don't just check if the index is a "content" index, because
many of the tests make indexes which are neither content or auxilary
indexes (eg, "rummager_test"), and these should have popularity values
added.

Previously, we were only adding popularity fields to indexes when a
popularity value was found matching the value of the "link" field.  This
meant that most of our tests were producing documents without a
popularity value.  It turns out that elasticsearch 0.90 is more fussy
about the popularity field existing when used in a script than 0.20, and
as such VMs running 0.90.12 fail their integration tests.

This probably doesn't affect production.  It could if:
 - the page-traffic index went missing on production
 - an index migration was performed
 - no documents contained a popularity value
Merge pull request #231 from alphagov/always_set_popularity

Always add popularity to content indexes
Whitespace.
Provide metasearch (best_bets) mappings for tests.

Removes unused `elasticsearch_schema.fixture.yml`.
Add debugger for integration tests.
Pass type to search to Index.raw_search

Allow the document type to be passed to raw_search, so that we can just
search for, say, documents of type best_bet.
Add metasearch_index_name to the config
Add BestBetsChecker to look up best bets

This fetches best bets from the metasearch index, and merges multiple
best bets appropriately.
Tell test helper about metasearch helper
Raise a clearer error for invalid index names