Inject command into userdata

The injected command touches /var/lib/cloud/instance/provision-finished
so it is easily determinable if provision has been completed.

Change-Id: Ib5b93f7bd14f533af41182ffdab6a029a3b9e13a
Signed-off-by: Jeff Peeler <jpeeler@redhat.com>

heat/engine/instance.py

@@ -191,6 +191,7 @@ class Instance(resources.Resource):
     def handle_create(self):
         security_groups = self.properties.get('SecurityGroups')
         userdata = self.properties['UserData']
+        userdata += 'touch /var/lib/cloud/instance/provision-finished\n'
         flavor = self.properties['InstanceType']
         key_name = self.properties['KeyName']