Merge panko tempest config into ceilometer repo

* https://review.openstack.org/525072 removes the dummy panko
  tempest plugin from panko repo but panko tempest config is used
  in ceilometer integration tests. It merges the required config
  in order to avoid turbulence in integration tests.


Change-Id: I97a5abed3486f63363782f52e7746e87bd88ed4a
diff --git a/ceilometer/tests/tempest/plugin.py b/ceilometer/tests/tempest/plugin.py
index bfc6b40..19fcf68 100644
--- a/ceilometer/tests/tempest/plugin.py
+++ b/ceilometer/tests/tempest/plugin.py
@@ -15,6 +15,7 @@
 
 import os
 
+from tempest import config
 from tempest.test_discover import plugins
 
 import ceilometer
@@ -31,13 +32,20 @@
         return full_test_dir, base_path
 
     def register_opts(self, conf):
-        conf.register_group(tempest_config.telemetry_group)
-        conf.register_opts(tempest_config.TelemetryGroup, group='telemetry')
-        conf.register_opt(tempest_config.service_option,
-                          group='service_available')
+        config.register_opt_group(
+            conf, config.service_available_group,
+            tempest_config.service_option)
+        config.register_opt_group(
+            conf, tempest_config.telemetry_group,
+            tempest_config.TelemetryGroup)
+        config.register_opt_group(
+            conf, tempest_config.event_group,
+            tempest_config.event_opts)
 
     def get_opt_lists(self):
-        return [
-            (tempest_config.telemetry_group.name,
-             tempest_config.TelemetryGroup),
-            ('service_available', [tempest_config.service_option])]
+        return [(tempest_config.telemetry_group.name,
+                 tempest_config.TelemetryGroup),
+                (tempest_config.event_group.name,
+                 tempest_config.event_opts),
+                (config.service_available_group.name,
+                 tempest_config.service_option)]