Use olso.log directly

As the openstack/common is deprecated, Watcher should use oslo lib
directly to run in the openstack env. So there is much work to do
with oslo. This patch fixed the log part.

Change-Id: I3145a842fe3a22b3d08fec60d180329073edd50f

watcher/opts.py

@@ -16,12 +16,12 @@
 # limitations under the License.
 
 import itertools
+from oslo_log import _options
 
 import watcher.api.app
 from watcher.applier.framework import manager_applier
 import watcher.common.messaging.messaging_core
 
-import watcher.openstack.common.log
 
 from watcher.decision_engine.framework import manager_decision_engine
 from watcher.decision_engine.framework.strategy import strategy_loader
@@ -33,10 +33,10 @@ from watcher.metrics_engine.framework.datasources import influxdb_collector
 def list_opts():
     return [
         ('DEFAULT', itertools.chain(
-            watcher.openstack.common.log.generic_log_opts,
-            watcher.openstack.common.log.log_opts,
-            watcher.openstack.common.log.common_cli_opts,
-            watcher.openstack.common.log.logging_cli_opts
+            _options.generic_log_opts,
+            _options.log_opts,
+            _options.common_cli_opts,
+            _options.logging_cli_opts
         )),
         ('api', watcher.api.app.API_SERVICE_OPTS),
         ('watcher_messaging',