trace down paging test failure

[rahulbot]

As demonstrated on the the test_paged_articles_all test, paging is failing. We need to track down why this is happening either here or on news-search-api. I'm making the initial issue here to capture the test failure, though I realize the resolution might lie in another repo.

[pgulley]

First step is to get the changes which allow us to query against the collections alias mc_search implemented- currently investigating on a dev stack.

[rahulbot]

Solution is to sort by indexed_date. See mediacloud/news-search-api#64 for potential system-wide resolution.