Follow the new PTI for building docs

For compliance with the Project Testing Interface as described in:
https://governance.openstack.org/tc/reference/project-testing-interface.html#documentation
http://lists.openstack.org/pipermail/openstack-dev/2017-December/125710.html
http://lists.openstack.org/pipermail/openstack-dev/2018-March/128594.html

Change-Id: I86d2460231d246005cfdace75c50dc54c137f0ca

watcher/api/app.py

@@ -21,7 +21,7 @@ import pecan
 
 from watcher.api import acl
 from watcher.api import config as api_config
-from watcher.api import middleware
+from watcher.api.middleware import parsable_error
 from watcher import conf
 
 CONF = conf.CONF
@@ -42,7 +42,7 @@ def setup_app(config=None):
         app_conf.pop('root'),
         logging=getattr(config, 'logging', {}),
         debug=CONF.debug,
-        wrap_app=middleware.ParsableErrorMiddleware,
+        wrap_app=parsable_error.ParsableErrorMiddleware,
         **app_conf
     )
 

watcher/api/middleware/__init__.py

@@ -1,25 +0,0 @@
-# -*- encoding: utf-8 -*-
-#
-# 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 watcher.api.middleware import auth_token
-from watcher.api.middleware import parsable_error
-
-
-ParsableErrorMiddleware = parsable_error.ParsableErrorMiddleware
-AuthTokenMiddleware = auth_token.AuthTokenMiddleware
-
-__all__ = (ParsableErrorMiddleware,
-           AuthTokenMiddleware)