bifrost does not support RedHat rpm installation, in this patch,
added RedHat rpms list, and replace 'apt' Ubuntu command to ansible
pkg_mgr var to support both Ubuntu and RedHat.
And remove the duplication testing packages installation section.
Closes-bug: 1456896
Change-Id: I58d627d3deb4a8a2712f242429e93b8ded9cfb76