update build and dependencies to eliminate known vulnerabilities

gulpfile.js

@@ -1,6 +1,4 @@
 const gulp = require('gulp');
-const path = require('path');
-const runSequence = require('run-sequence');
 const connect = require('gulp-connect');
 const livereload = require('gulp-livereload');
 const run = require('gulp-run');
@@ -16,24 +14,25 @@ const paths = {
 
 // connects the server at given port and root.
 // enables the live reloading.
-gulp.task('connect', () => {
-  return connect.server({
+gulp.task('connect', done => {
+  connect.server({
       livereload: true,
       root: paths.distDir,
       port: port
   });
+  done();
 });
 
-gulp.task('listen', ()=>{
-  livereload.listen();
+gulp.task('listen', done => {
+  livereload.listen(done);
 });
 
-gulp.task('connect-and-listen', ()=>{
-  runSequence('connect', 'listen');
-});
 
-gulp.task('reload', function(){
+gulp.task('connect-and-listen', gulp.series('connect', 'listen'));
+
+gulp.task('reload', done => {
   livereload.reload();
+  done();
 });
 
 // use gulp-run in the middle of a pipeline:
@@ -42,11 +41,11 @@ gulp.task('rebuild', function() {
 });
 
 gulp.task('watch', ()=>{
-  gulp.watch(["src/**/*"], ['rebuild']);
+  return gulp.watch(["src/**/*"], gulp.series('rebuild'));
 });
 
 gulp.task('zip', function(){
-  gulp.src(['dist/unpacked/**'])
-  .pipe(gzip('extension.zip'))
-  .pipe(gulp.dest('dist'))
+  return gulp.src(['dist/unpacked/**'])
+    .pipe(gzip('extension.zip'))
+    .pipe(gulp.dest('dist'))
 })

package.json

@@ -24,9 +24,9 @@
     "copy-webpack-plugin": "^4.5.1",
     "css-loader": "^0.28.11",
     "file-loader": "^1.1.11",
-    "gulp": "^3.9.1",
+    "gulp": "^4.0.0",
     "gulp-connect": "^5.5.0",
-    "gulp-livereload": "^3.8.1",
+    "gulp-livereload": "^4.0.1",
     "gulp-run": "^1.7.1",
     "gulp-zip": "^4.1.0",
     "html-loader": "^0.5.5",
@@ -38,8 +38,8 @@
     "run-sequence": "^2.2.1",
     "sass-loader": "^7.0.1",
     "style-loader": "^0.21.0",
-    "webpack": "^4.8.1",
-    "webpack-cli": "^2.1.3",
+    "webpack": "^4.20.2",
+    "webpack-cli": "^3.1.1",
     "webpack-dev-server": "^3.1.4",
     "webpack-merge": "^4.1.2",
     "webpack-shell-plugin": "^0.5.0"