[atomic] CentOS Atomic Host Alpha 2016.0.175

[Colin Walters <walters verbum org>]

Hi, you may have seen the recent CentOS AH blog:

http://www.projectatomic.io/blog/2016/07/new-centos-atomic-host-releases-available-for-download/

I've now reworked

https://wiki.centos.org/SpecialInterestGroup/Atomic/Devel

and the release scripts to include a new middle ground, an "alpha" branch.
This provides a level of stability between the "continuous" stream and the
Core SIG rebuilds.  It's just an OSTree branch, so you can rebase to it.

rpm-ostree rebase -r centos-atomic-continuous:centos-atomic-host/7/x86_64/devel/alpha

We expect to do more work on release engineering here.