Auto-generate sample config file

This PS auto-generates the sample config file using
oslo-config-generator which is how every project should reliably
produce a config file.

In addition, the Patrole documentation was updated to link to the
generated config file, so that the documentation accurately
shows config options.

Change-Id: Ib3c39084b4c2b5a0078d1293d882cf9a9050b29b
Closes-Bug: #1709490
diff --git a/setup.cfg b/setup.cfg
index b3f4312..d805f62 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -54,3 +54,5 @@
 [entry_points]
 tempest.test_plugins =
     patrole_tempest_plugin = patrole_tempest_plugin.plugin:PatroleTempestPlugin
+oslo.config.opts =
+    patrole.config = patrole_tempest_plugin.config:list_opts