Revert "Revert "Revert change maybe to use dnf instead of yum""
Revert "Revert "Revert change maybe to use dnf instead of yum""

This reverts commit 47b39e3fdf597c92f1737474f0675ab851147fee.

Trophime/singularity,Trophime/singularity,Trophime/singularity,Trophime/singularity