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/tox.ini b/tox.ini
index f1b5b86..3f2cfcd 100644
--- a/tox.ini
+++ b/tox.ini
@@ -55,6 +55,9 @@
 [testenv:debug]
 commands = oslo_debug_helper -t patrole_tempest_plugin/tests {posargs}
 
+[testenv:genconfig]
+commands = oslo-config-generator --config-file etc/config-generator.patrole.conf
+
 [flake8]
 enable-extensions = H106,H203,H904
 show-source = True