Skip Ubuntu server test case because of flaky failures.

Change-Id: Ie3b450f06f7606d4e9dda66df38185784fc94fa8

tobiko/tests/functional/openstack/stacks/test_ubuntu.py

@@ -15,12 +15,15 @@
 #    under the License.
 from __future__ import absolute_import
 
+import testtools
+
 import tobiko
 from tobiko.shell import sh
 from tobiko.openstack import stacks
 from tobiko.tests.functional.openstack.stacks import test_cirros
 
 
+@testtools.skip('BUG: this often fails probably because of some timeout')
 class UbuntuServerStackTest(test_cirros.CirrosServerStackTest):
     """Tests connectivity to Nova instances via floating IPs"""