Remove deprecated database.url option

It has been deprecated in Ocata release. `database.connection` should be
used instead.

Change-Id: I8ed5f0e248531e1cada182e43cebe44edb324148
Story: 2004257
Task: 27793

monasca_api/conf/database.py

@@ -1,35 +0,0 @@
-# Copyright 2017 FUJITSU LIMITED
-#
-# 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.
-
-from oslo_config import cfg
-
-url_opt = cfg.StrOpt(name='url',
-                     default='$database.connection',
-                     help='''
-The SQLAlchemy connection string to use to connect to the database
-''',
-                     required=False,
-                     deprecated_for_removal=True,
-                     deprecated_since='1.6.0',
-                     deprecated_reason='Please use database.connection option,'
-                                       'database.url is scheduled for removal '
-                                       'in Pike release')
-
-
-def register_opts(conf):
-    conf.register_opt(url_opt, 'database')
-
-
-def list_opts():
-    return 'database', [url_opt]

releasenotes/notes/remove-database-url-option-efd6c09b771063c0.yaml

@@ -0,0 +1,5 @@
+---
+upgrade:
+  - |
+    Deprecated configuration option ``database.url`` has been removed. Please
+    use ``database.connection`` instead.