doc: remove contacts from Readme

The twitter and google forum is
not maintained and doesnt have
any updates, This is the good
chance to remove the same from
the cephcsi readme as well.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

README.md

@@ -208,5 +208,3 @@ Please use the following to reach members of the community:
   on the [ceph Slack](https://ceph-storage.slack.com) to discuss anything
   related to this project. You can join the Slack by this
   [invite link](https://bit.ly/ceph-slack-invite)
-- Forums: [ceph-csi](https://groups.google.com/forum/#!forum/ceph-csi)
-- Twitter: [@CephCsi](https://twitter.com/CephCsi)