Elasticsearch-query

* 9 - Add integration tests, test coverage is now at 99%
* 11 - Introduce `count()` method
* 4 - Implement `query_by_sql()` method

This package (and the repository) is now called `elasticsearch-query` - 7

6 - dependencies upgraded

* 3 - wikia_common_kibana | allow to provide a list of fields to be returned by elastic