The contributing.rst file was referencing a non-existing path, and
index.rst referenced a non-existing usage.rst file.
Added build-openstack-sphinx-docs job to test doc changes
Change-Id: I0efd9a2f652f89df0eba88b5b95e66ee9ab44af2
This tempest plugin is being split out of the main mistral project in
accordance with Queens goal "Split Tempest Plugins into Separate
Repos/Projects"[1]. This patch applies the standard boilerplate files
for OpenStack projects so that it can stand on its own.
[1] https://governance.openstack.org/tc/goals/queens/split-tempest-plugins.html