Vagrantfile: Switch to use CentOS Atomic Host

[cgwalters]

Just putting this out there for discussion. I didn't try switching the development box - if we wanted to do that it should be done via a "pet container". Given we already have the Dockerfile I think doing a docker build of that in the provisioner would work.

[ashcrow]

Thanks @cgwalters! I'll give it a run and see how things go.

[cooktheryan]

@ashcrow a couple nits

• sudo hostnamectl set-hostname fedora-cloud to sudo hostnamectl set-hostname atomic-node or something similar
• remove # End etcd
• should we add the atomic host upgrade back in or is it unnecessary?

[cgwalters]

Updated for review comments. I didn't add atomic host upgrade - we should keep the vagrant boxes fresh enough.

[ashcrow]

@cgwalters fair enough. The changes look good to me. @cooktheryan what do you think?

[mbarnes]

Not clear to me why the IP addresses are changed, but the end-to-end tests under /features should be updated to match. (Also, this would be a good time to add a simple hostname lookup table for these tests so the IP addresses aren't spread all over.)

[rh-atomic-bot]

:umbrella: The latest upstream changes (presumably #187) made this pull request unmergeable. Please resolve the merge conflicts.