migrate to gulp 3.7.0 for node-liftoff support
migrate to gulp 3.7.0 for node-liftoff support

caasi/react-ld31,caasi/seed,caasi/countdown,caasi/react-colorpicker,caasi/react-coc-sheet,caasi/prototype-ly-diff,ChineseCubes/react-vtt,caasi/react-coc-sheet,caasi/prototype-odf,ChineseCubes/audio-playback,caasi/seed,caasi/prototype-stg