openstack_vms: update novaclient auth

The openstack novaclient has updated it's auth mechanism, deprecating
the method used in this module.  This patch updates the novaclient
authentication call to leverage this new auth method.

i3pystatus/openstack_vms.py

@@ -1,6 +1,6 @@
 from i3pystatus import IntervalModule
 # requires python-novaclient
-from novaclient.v2 import client
+from novaclient import client
 import webbrowser
 
 
@@ -35,6 +35,7 @@ class Openstack_vms(IntervalModule):
 
     def run(self):
         nclient = client.Client(
+            '2.0',
             self.username,
             self.password,
             self.tenant_name,