Use pbr wsgi_scripts to install Cinder WSGI entry point

pbr 1.4.0 added support for wsgi_scripts that creates scripts for wsgi
servers on install.

Change-Id: Ifbab059001d1567b1f7b394c0411a9ca4629f846
Closes-Bug: #1500367

cinder/wsgi/wsgi.py

@@ -35,7 +35,7 @@ from cinder.wsgi import common as wsgi_common
 CONF = cfg.CONF
 
 
-def _application():
+def initialize_application():
     objects.register_all()
     CONF(sys.argv[1:], project='cinder',
          version=version.version_string())
@@ -43,6 +43,3 @@ def _application():
 
     rpc.init(CONF)
     return wsgi_common.Loader().load_app(name='osapi_volume')
-
-
-application = _application()

setup.cfg

@@ -58,6 +58,8 @@ console_scripts =
     cinder-scheduler = cinder.cmd.scheduler:main
     cinder-volume = cinder.cmd.volume:main
     cinder-volume-usage-audit = cinder.cmd.volume_usage_audit:main
+wsgi_scripts =
+    cinder-wsgi = cinder.wsgi.wsgi:initialize_application
 # These are for backwards compat with Havana notification_driver configuration values
 oslo_messaging.notify.drivers =
     cinder.openstack.common.notifier.log_notifier = oslo_messaging.notify._impl_log:LogDriver