The canonical spec file is now upstream since:
https://github.com/projectatomic/rpm-ostree/pull/1900
Add a script to make it trivial to import the spec file here and merge
the changelog. There's a `--keep-v-r` flag one can use to keep the
Version and Release tags of the existing spec file to deal with e.g. git
snapshots (though ideally continuous builds will eventually be handled
automatically).
