I’m not sure that either we, or Fedora, want us to carry the .spec files in the Mir source tree - the Debian packaging is somewhat special, due to our (ambitions of) continuous-release-into-Ubuntu workflow.
We should definitely test that Mir can build on Fedora, but I think that would be adequately solved by adding a Fedora target to Travis and running the commands you’ve listed here.
We’d only want to carry the .spec file in source control if we were planning to have a autobuilt mir-devel COPR, like our devel PPA. Which could be useful, but might be a stretch goal?
I don’t think we want to maintain packaging for all the various distros people might want to use Mir on, and I don’t think the various distros would want us to maintain packaging for it, either.