readme: add google group

README.md

@@ -5,7 +5,7 @@
 [![Coverage Status](https://coveralls.io/repos/ory-am/hydra/badge.svg?branch=master&service=github)](https://coveralls.io/github/ory-am/hydra?branch=master)
 [![Go Report Card](https://goreportcard.com/badge/github.com/ory-am/hydra)](https://goreportcard.com/report/github.com/ory-am/hydra)
 
-Hydra is being developed by german-based company [Ory](https://ory.am). Join our [mailinglist](http://eepurl.com/bKT3N9) to stay on top of new developments.
+Hydra is being developed by german-based company [Ory](https://ory.am). Join our [mailinglist](http://eepurl.com/bKT3N9) to stay on top of new developments. There is also a [Google Group](https://groups.google.com/forum/#!forum/ory-hydra/new) and a [Gitter Channel](https://gitter.im/ory-am/hydra).
 
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