Skip test that is failing due to nova bug 940500.

Change-Id: I3c3b78431c44d3cc40cbb9d019c496e0fcfbd081
diff --git a/tempest/tests/test_list_floating_ips.py b/tempest/tests/test_list_floating_ips.py
index 2de6d6b..e22dd58 100644
--- a/tempest/tests/test_list_floating_ips.py
+++ b/tempest/tests/test_list_floating_ips.py
@@ -58,6 +58,7 @@
         self.client.delete_floating_ip(floating_ip_id)
 
     @attr(type='negative')
+    @unittest.skip('Skipping until Nova Bug 940500 is fixed')
     def test_get_nonexistant_floating_ip_details(self):
         """
         Negative test:Should not be able to GET the details