Experimenting with splitting up the logging of the request URL.
Adjust elasticsearch config for the path hierarchy field.
Merge branch 'master' into log-urls
Lots of updates to the elasticsearch logging stuff:

This commit has gotten a bit unwieldy but it contains the following:

- Log a few additional header fields: Accept, Connection, Referer,
  HTTP basic auth usernames, and the user's registration source.
- Fill in the API key and user details if possible when dealing with
  only nginx logs (so when the gatekeeper wasn't being hit)
- Switch from 'elasticsearchclient' to the new, official 'elasticsearch'
  library. The new library made bulk search/scan easier.
- Change the elasticsearch index names to contain the current
  environment (development, production, etc). This is so we can use the
  development elasticsearch database for unit test data without stepping
  on each other's toes.
Fix log cleaner handling in migration script.