Add 'rhel' to list for RPM based distros. Also sort the distro
list for rpm packages for affected lines.
Change-Id: Ied4cb3e9763d6c6359f314d16185383ac3e006ed
Partially-Implements: blueprint rhel-based-image-support
Updated build.py to reflect this change.
Deprecate --template option and make it a noop.
Change-Id: I7cd98d1ee684a4c64984a49597159868152683b2
Partially-Implements: blueprint remove-docker-dir