respect the virtualenv by using /usr/bin/env

Signed-off-by: S.Çağlar Onur <caglar@10ur.org>
diff --git a/planetstack/openstack_observer/ceilometer.py b/planetstack/openstack_observer/ceilometer.py
index e34b000..9944a9c 100644
--- a/planetstack/openstack_observer/ceilometer.py
+++ b/planetstack/openstack_observer/ceilometer.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
 from ceilometerclient import client