Add basic sphinx docs setup with some rudimentary information
on how to use gabbi-tempest. This isn't perfect but provides
the basics for future improvement.
A docs template is added to .zuul.yaml.
Change-Id: If2631d92366866ba6bd149909ece17734931ae91
In this way the plugin becomes generic: point it at some directories
that contain gabbi YAML files that use the provided environment
variables (see the README.rst), what them run.
One concern that will need to be address is dealing with parallelism:
tempest doesn't make it easy to manipulate the group_regex.
This is entirely the result of @sileht, who got things working for
gnocchi.
The end game here is a generic way to have a suite of YAML files
sitting around somewhere and run them, via tempest, and for it
to just work. This is currently some distance away from that
(because I got distracted finding nova bugs).
Chris Dent