add the servant (haskell) packages to nixpkgs
use camelCase instead of dashes for servant package names in haskell-packages.nix
rename nix files to default.nix for all servant pkgs
servant-scotty/default.nix: switch to version 0.1.1 which relaxes the bounds on the transformers package
Merge pull request #2 from zalora/add-servant

Add servant