[atomic] Centos Atomic 7.0 -> 7.1

[Colin Walters <walters verbum org>]

Users of CentOS Atomic 7 will hit this error on upgrading now:

# atomic upgrade
Updating from: centos-atomic-host:centos/7/atomic/x86_64/cloud-docker-host
 
Receiving objects: 24% (1436/5931) 308.3 kB/s 34.2 MB          
error: fsetxattr: Invalid argument

What's happening here is that this is a full atomic switch from a CentOS 7.0 to CentOS 7.1 base - but we're using the old selinux policy to do it.  The 7.0 SELinux policy had a bug with respect to rpm-ostree that caused a domain transition to not occur.

You can work around this with:

# runcon -r system_r -t install_t atomic upgrade

This workaround will only be necessary one time - after that the 7.1 SELinux policy will be in place and the correct domain transition will occur.