updated gulp to V4

sites/all/modules/gui/materiobasemod/gulpfile.js

@@ -10,18 +10,17 @@ function handleError(err) {
   // this.emit('end');
 }
 
-gulp.task('scripts', function () {
-    gulp.src('./js/*.js')
-        .pipe(jsmin())
-        .pipe(rename({suffix: '.min'}))
-        .pipe(gulp.dest('./js/dist/'));
+gulp.task('scripts', done => {
+  gulp.src('./js/*.js')
+      .pipe(jsmin())
+      .pipe(rename({suffix: '.min'}))
+      .pipe(gulp.dest('./js/dist/'));
+  done()
 });
 
 
-gulp.task('default', function () {
-});
-
 // default gulp task
-gulp.task('default', ['scripts'], function() {
-  gulp.watch('./js/*.js', ['scripts']);
-});
+gulp.task('default', gulp.series('scripts', function(done) {
+  gulp.watch('./js/*.js', gulp.series('scripts'));
+  done()
+}));