Drop rpm packaging
This packaging (if it works) only work for python2 and we're going to drop
python2 support.
I don't have an rpm build environment and I don't known how to test this, so
just drop the spec file and let someone revive this if needed.
TODO list for the rql package
=============================
* retirer les restrictions e_type = [A-Z][a-z_]*
r_type = [a-z_]*
* detecter les erreurs ASAP pour éviter stcheck
* tests unitaires pour sqlgen
* revoir tutoriel
* specification 1.0