pylorax users will need to change to using dnf and pass a dnf.Base()
object as the dbo argument instead of a yum object as the yum or ybo
argument. See the lorax script for an example of how to do this.
The lorax cmdline argument --excludepkgs has been removed since dnf
doesn't appear to have any way to support it and packages should be
controlled using templates anyway.
Brian C. Lane