Add *.spec file for RPM builds
Created by: julianrichen
This PR adds a SPEC file for creating RPM builds for Fedora, RHEL, etc.. I know Purism's PureOS is based on Debian but for those users on RPM ditros that want to contribute it would be nice to easily download & install libhandy via an RPM.
Before it will really be accepted in Fedora a proper release would need to be made instead of 0.0.0. The deb was also version-ed at 0.0.0 so I set that.
Purism could also have test builds via COPR which aren't the official Fedora repo but allows Fedora users to try software, like Ubuntu's PPAs.