Log Message:
Update databases/py-elasticsearch to 5.0.1.

5.0.1 (2016-11-02)
- Fixed performance regression in scan helper

5.0.0 (2016-10-19)
- Version compatible with elasticsearch 5.0

- when using SSL certificate validation is now on by default.
  Install certifi or supply root certificate bundle.
- elasticsearch.trace logger now also logs failed requests, signature
  of internal logging method log_request_fail has changed, all custom
  connection classes need to be updated
- added headers arg to connections to support custom http headers
- passing in a keyword parameter with None as value will cause that
  param to be ignored