added 2.4.0 changelog

Author: honzakral

Changelog.rst

@@ -12,6 +12,18 @@ Version compatible with elasticsearch 5.0
  * passing in a keyword parameter with ``None`` as value will cause that param
    to be ignored 
 
+2.4.0 (2016-08-17)
+------------------
+
+ * ``ping`` now ignores all ``TransportError`` exceptions and just returns
+   ``False``
+ * expose ``scroll_id`` on ``ScanError``
+ * increase default size for ``scan`` helper to 1000
+
+Internal:
+
+ * changed ``Transport.perform_request`` to just return the body, not status as well.
+
 2.3.0 (2016-02-29)
 ------------------