jenkinsci/mesos-plugin — pull request #65 by RsrchBoy (2014-10-20 21:56:06+00:00)
Title: Use the official Ubuntu vagrant image

...to cut down on disk space usage (if people already have this image
downloaded), and use the "official" image.

I believe this is what the Vagrantfile was already doing, and doing correctly;
with the introduction of "vagrantcloud" the semantics just changed a bit.