Show team and repo badges on README

This patch adds the team's and repository's badges to the README file.
The motivation behind this is to communicate the project status and
features at first glance.

For more information about this effort, please read this email thread:

http://lists.openstack.org/pipermail/openstack-dev/2016-October/105562.html

To see an example of how this would look like check:

b'https://gist.github.com/99cdb23eb3f1e889f3bd084ef2cf1a18\n'

Change-Id: I9c0c6e5165257ecf3f76522cd6a6d6555add0ed2

README.rst

@@ -1,3 +1,12 @@
+========================
+Team and repository tags
+========================
+
+.. image:: http://governance.openstack.org/badges/python-congressclient.svg
+    :target: http://governance.openstack.org/reference/tags/index.html
+
+.. Change things from this point on
+
 ===============================
 python-congressclient
 ===============================