Updated gulp file to stop using deprecated features. The versions are locked

beacon/gulpfile.js

@@ -2,7 +2,8 @@ var gulp = require('gulp'),
     gulp_uglify = require('gulp-uglify'),
     gulp_clean_css = require('gulp-clean-css'),
     gulp_concat = require('gulp-concat'),
-    gulp_inject = require('gulp-inject');
+    gulp_inject = require('gulp-inject'),
+    merge_stream = require('merge-stream');
 
 var css_path = 'src/*.css',
     js_path = 'src/*.js',
@@ -34,7 +35,7 @@ gulp.task('js', function() {
         .pipe(gulp.dest('static'));
 });
 
-gulp.task('templates', ['css', 'js', 'png', 'svg'], function() {
+gulp.task('templates', function() {
     return gulp.src(template_path)
         .pipe(gulp_inject(gulp.src('static/*.js', {read:false}), {
                             transform: function(filepath) {
@@ -51,12 +52,7 @@ gulp.task('templates', ['css', 'js', 'png', 'svg'], function() {
         .pipe(gulp.dest('templates'));
 });
 
-gulp.task('watch', function() {
-    gulp.watch(css_path, ['css']);
-    gulp.watch(js_path , ['js']);
-    gulp.watch(png_path , ['png']);
-    gulp.watch(png_path , ['svg']);
-    gulp.watch(template_path, ['templates']);
-});
-
-gulp.task('default', ['png', 'svg', 'css', 'js', 'templates']);
\ No newline at end of file
+gulp.task('default', gulp.series(
+    gulp.parallel('css', 'js', 'png', 'svg'),
+    'templates'
+));
\ No newline at end of file

beacon/package.json

 {
-    "devDependencies": {
-        "gulp": "3.9.1",
-        "gulp-uglify": "latest",
-        "gulp-concat": "latest",
-        "gulp-clean-css": "latest",
-        "gulp-inject": "latest"
-    }
+  "devDependencies": {
+    "gulp": "4.0.0",
+    "gulp-uglify": "3.0.1",
+    "gulp-concat": "2.6.1",
+    "gulp-clean-css": "4.0.0",
+    "gulp-inject": "5.0.2",
+    "merge-stream": "^1.0.1"
+  }
 }