Description of problem: Currently dnf module install ends with 'nothing to do' message when there is nothing to install. It should be changed to something like "No packages installed. %s modules were enabled.
Merged in https://github.com/rpm-software-management/dnf/tree/wip/modularity
This bug appears to have been reported against 'rawhide' during the Fedora 28 development cycle. Changing version to '28'.