Open Stack

Hi,

I recently found out that some projects in OpenStack do not gate on
CentOS platform, while it's one of the most popular disto used to
deploy OpenStack in production, after Ubuntu.
I've decided to start a discussion and see if we would agree to
officially make the statement that we support Ubuntu and CentOS and we
commit to test these distros in project gates, like it's already the
case for a lot of projects.

https://review.openstack.org/#/c/402940/

Feel free to give any feedback,
Thanks!
-- 
Emilien Macchi