Can't run the launcher to install Discourse on CentOS 7

I just bought another VPS.
It’s from OVH.
It has Ubuntu 14.04
It has all of the requirements. Followed this: http://www.howtoinstalldiscourse.com/how-to-install-discourse-on-ubuntu/ tutorial.

AND I GOT THE SAME DAMN ERROR.

Device "docker0" does not exist.
time="2014-12-13T14:49:23-05:00" level="fatal" msg="Cannot connect to the Docker daemon. Is 'docker -d' running on this host?" 
Cannot connect to the docker daemon - verify it is running and you have access

Do you have Skype or something? If your able to install it for me, that would be great, because I don’t want to waste any more money on VPS’s. I also don’t know how to remove the old Docker/Discourse.

I REALLY need help here.