Add nix derivation for skygear-server
Add nix derivation for skygear-server

rickmak/skygear-server,SkygearIO/skygear-server,rickmak/skygear-server,SkygearIO/skygear-server,SkygearIO/skygear-server,SkygearIO/skygear-server,rickmak/skygear-server