Remove mention of RHEL from README since dnf is not yet the default package manager there.
Remove mention of RHEL from README since dnf is not yet the default package manager there.

eriknstr/klondike,eriknstr/klondike,eriknstr/klondike,ICT-Infer/klondike,ICT-Infer/klondike,en90/klondike,eriknstr/klondike,en90/klondike,ICT-Infer/klondike,ICT-Infer/klondike