Description of problem:
Fedora 22 is planning to switch over to dnf from yum as per
Please switch from yum/yum-utils to dnf. Thanks!
For f22 we need to transition to using livemedia-creator so that it can take advantage of Anaconda's dnf support.
For f22 the compose tools (pungi, lorax, livecd-creator) will continue to use yum. For F23 lorax and pungi will move to using DNF and livemedia-creator should be used instead of livecd-creator for live media).