Add example per-dashboard settings.py

Now Horizon supports independent settings.py to define parameters
specific to each dashboard. This change introduces an example
settings.py for Desiangte dashboard.

Change-Id: Ib4d54c866fd505979d8afabadd0817cfe23920e0

designatedashboard/local_settings.d/_1799_dns_settings.py

@@ -0,0 +1,30 @@
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+# This file is to be included for configuring application which relates
+# to dns(Designate) functions.
+
+from django.conf import settings
+
+
+settings.POLICY_FILES.update({
+    'dns': 'designate_policy.yaml',
+})
+
+# Sample
+# settings.LOGGING['loggers'].update({
+#     'designateclient': {
+#         'handlers': ['console'],
+#         'level': 'DEBUG',
+#         'propagate': False,
+#     }
+# })