Remove all sphinx warnings

This patch set fixes all sphinx warnings and makes
https://docs.openstack.org/watcher/latest/configuration/index.html
available.

Change-Id: I76a715c10cb1d582419ff37869093fa9b8678310

etc/watcher/oslo-config-generator/watcher.conf

@@ -0,0 +1,16 @@
+[DEFAULT]
+output_file = etc/watcher/watcher.conf.sample
+wrap_width = 79
+
+namespace = watcher
+namespace = keystonemiddleware.auth_token
+namespace = oslo.cache
+namespace = oslo.concurrency
+namespace = oslo.db
+namespace = oslo.log
+namespace = oslo.messaging
+namespace = oslo.policy
+namespace = oslo.reports
+namespace = oslo.service.periodic_task
+namespace = oslo.service.service
+namespace = oslo.service.wsgi