Use standard logging in oslo.policy

Oslo libraries should not depend on oslo.log, we should use
standard logging, as noted in the graduation guidelines.

partially implements bp graduate-policy

Change-Id: I9d3973ad4b5b32922fa56881b679ad9e403289ea

oslo_policy/_parser.py

@@ -14,9 +14,10 @@
 #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 #    License for the specific language governing permissions and limitations
 #    under the License.
+
+import logging
 import re
 
-from oslo_log import log as logging
 import six
 
 from oslo_policy import _checks

oslo_policy/policy.py

@@ -202,10 +202,10 @@ by setting the ``policy_default_rule`` configuration setting to the
 desired rule name.
 """
 
+import logging
 import os
 
 from oslo_config import cfg
-from oslo_log import log as logging
 from oslo_serialization import jsonutils
 import six
 

requirements.txt

@@ -4,5 +4,4 @@
 
 oslo.config>=1.6.0         # Apache-2.0
 oslo.i18n>=1.3.0  # Apache-2.0
-oslo.log>=0.1.0            # Apache-2.0
 oslo.serialization>=1.2.0  # Apache-2.0