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:

https://gist.github.com/5bcdfae778a1e96da9cfd238ee26e5d8

Change-Id: I166f62954f811b2ed91a3a8d4a2caeefaedd1c78
diff --git a/README.rst b/README.rst
index 87f4736..09d8191 100644
--- a/README.rst
+++ b/README.rst
@@ -1,3 +1,12 @@
+========================
+Team and repository tags
+========================
+
+.. image:: http://governance.openstack.org/badges/designate-tempest-plugin.svg
+    :target: http://governance.openstack.org/reference/tags/index.html
+
+.. Change things from this point on
+
 ================================
 Tempest Integration of Designate
 ================================