Change template names to queens

The new master branch should point now to queens instead of pike.

So, HOT templates should specify that they might contain features
for queens release [1]

[1]: https://docs.openstack.org/heat/latest/template_guide/hot_spec.html#queens

Change-Id: I7654d1c59db0c4508a9d7045f452612d22493004

deployed-server/deployed-server.yaml

@@ -1,4 +1,4 @@
-heat_template_version: pike
+heat_template_version: queens
 parameters:
   image:
     type: string