Cabal2Nix/Package.hs: store the package version as an ordinary string
Cabal2Nix/Package.hs: store the package version as an ordinary string

We don't need the abstract data type from Cabal.

gridaphobe/cabal2nix,dmalikov/cabal2nix,jb55/cabal2nix,bennofs/cabal2nix,psibi/cabal2nix,Fuuzetsu/cabal2nix,spencerjanssen/cabal2nix