hackage-packages.nix: update Haskell package set

This commit enables all haskellPackages builds so that we can discover builds
that have been fixed recently.

This update was generated by hackage2nix v20151217-12-g567601b using the following inputs:

  - Nixpkgs: https://github.com/NixOS/nixpkgs/commit/a67868f0602d13d13e2f21ffb43dac37910bb65e
  - Hackage: https://github.com/commercialhaskell/all-cabal-hashes/commit/1c84c94e147ab380bb0e954d13fd248238eb72b3
  - LTS Haskell: https://github.com/fpco/lts-haskell/commit/d2ad5fe9030deeacf1ed9c9de9045c65e597ca76
  - Stackage Nightly: https://github.com/fpco/stackage-nightly/commit/c1be20cfc01ee9f7431bc71f4377896ab2f352d2