Fix opam: the devel version depends on oasis
Fix opam: the devel version depends on oasis

fdopen/lwt,ocsigen/lwt,mfp/lwt,rgrinberg/lwt,c-cube/lwt,mirage/lwt,ocsigen/lwt,c-cube/lwt,rgrinberg/lwt,mirage/lwt,mfp/lwt,rgrinberg/lwt,rgrinberg/lwt,c-cube/lwt,rneswold/lwt,rneswold/lwt,fdopen/lwt,ocsigen/lwt,rneswold/lwt