Update gulpfile.js to work with Gulp 4
Update gulpfile.js to work with Gulp 4

carakas/forkcms,jonasdekeukelaere/forkcms,jonasdekeukelaere/forkcms,jonasdekeukelaere/forkcms,sumocoders/forkcms,carakas/forkcms,carakas/forkcms,jonasdekeukelaere/forkcms,carakas/forkcms,sumocoders/forkcms,sumocoders/forkcms,carakas/forkcms,sumocoders/forkcms,sumocoders/forkcms,jonasdekeukelaere/forkcms