Rename noHaddck attribute to doHaddock.
Rename noHaddck attribute to doHaddock.

Fixes https://github.com/NixOS/cabal2nix/issues/63.

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