coreos-kernel: remove old 3.15.2 kernel version
coreos-kernel: bump to 3.15.7
Merge pull request #775 from gregkh/kernel_update

Kernel update
profiles: disable kerberos in SDK ssh client

Left over from the SDK's days at Google. Noticed this because the
SDK build failed after bumping the krb related packages yesterday.
Merge pull request #776 from marineam/nokrb

profiles: disable kerberos in SDK ssh client