Fix one last Namespace#mixins call.
Fix one last Namespace#mixins call.

jreinert/yard,travis-repos/yard,thomthom/yard,alexdowad/yard,alexdowad/yard,lsegal/yard,herosky/yard,jreinert/yard,jreinert/yard,amclain/yard,alexdowad/yard,amclain/yard,herosky/yard,lsegal/yard,iankronquist/yard,ohai/yard,ohai/yard,thomthom/yard,iankronquist/yard,travis-repos/yard,herosky/yard,ohai/yard,lsegal/yard,thomthom/yard,iankronquist/yard,amclain/yard