The oslo sphinxconfiggen module was added to the oslo.config
2.3.0 release. This enables config file generation as part of
the sphinx doc generation.
The generated config file will pick up the current config
options from the code base. And as an added bonus, it will
now be published to the docs.openstack.org site for easy
reference or download.
This also puts us inline with what other projects like Nova
are doing for sample config files and is the recommended
method from the Oslo team.
Change-Id: I912a97eb2686d3dc56e50d8641d7bd930179bc18