Fixed skip messages to match pillars

Change-Id: I5bdbaf7a2c6d59f68a37cb2213b8c31f64e742d3
diff --git a/cvp_checks/tests/test_nova_services.py b/cvp_checks/tests/test_nova_services.py
index 7332a49..84ca19b 100644
--- a/cvp_checks/tests/test_nova_services.py
+++ b/cvp_checks/tests/test_nova_services.py
@@ -1,8 +1,16 @@
+import pytest
+
+
 def test_nova_services_status(local_salt_client):
     result = local_salt_client.cmd(
         'keystone:server',
         'cmd.run',
         ['. /root/keystonerc; nova service-list | grep "down\|disabled" | grep -v "Forced down"'],
         expr_form='pillar')
+
+    if not result:
+        pytest.skip("Nova service or keystone:server pillar \
+        are not found on this environment.")
+
     assert result[result.keys()[0]] == '', \
         '''Some nova services are in wrong state'''