Updated gitter badge

Author: kszucs

README.rst

@@ -450,4 +450,5 @@ Special thanks
    :target: https://pypi.python.org/pypi/sparkit-learn
 .. |Gitter| image:: https://badges.gitter.im/Join%20Chat.svg
    :alt: Join the chat at https://gitter.im/lensacom/sparkit-learn
-   :target: https://gitter.im/lensacom/sparkit-learn
+   :target: https://gitter.im/lensacom/sparkit-learn?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge
+