Testing changes for Jenkins CI (#863)

* testing

* more fixes

* downgrade docker-compose file version cause jenkins

* fixing matrix

* back to elasticsearch_version

* skip py3.7 for now there's a bug

* add build badge and remove 3.3
Sphinx doesn't play nice with 3.3

* sphinx 1.7 drops support for python 3.3

* updating test matrix

* remove travis

* updating badges

README

@@ -141,6 +141,8 @@ limitations under the License.
 
 Build status
 ------------
+.. image:: https://readthedocs.org/projects/elasticsearch-py/badge/?version=latest&style=flat
+   :target: https://elasticsearch-py.readthedocs.io/en/master/
 
-.. image:: https://secure.travis-ci.org/elastic/elasticsearch-py.png
-   :target: https://travis-ci.org/elastic/elasticsearch-py
+.. image:: https://clients-ci.elastic.co/job/elastic+elasticsearch-py+master/badge/icon
+   :target: https://clients-ci.elastic.co/job/elastic+elasticsearch-py+master/