Switch go Gulp 4 for builds

.gitignore

@@ -1,5 +1,6 @@
 # Do not index node.js modules that are used for building
 node_modules
+package-lock.json
 
 # Do not index releases
 release
@@ -10,4 +11,3 @@ vendor/
 # Do not index composer files
 composer.phar
 composer.lock
-

Plugin.php

@@ -60,7 +60,7 @@ class Plugin extends \Mibew\Plugin\AbstractPlugin implements \Mibew\Plugin\Plugi
     }
 
     /**
-     * Returns pluing's version.
+     * Returns plugin's version.
      *
      * @return string
      */

README.md

@@ -5,7 +5,7 @@ Provides Slack notifications when initiate a chat
 
 ## Installation
 
-1. Get the archive with the plugin sources. At the moment the only option is to build the plugin from sources or grab it from the zip file.
+1. Get the archive with the plugin sources. You can download it from the [official site](https://mibew.org/plugins#mibew-slack) or build the plugin from sources.
 
 2. Untar/unzip the plugin's archive.
 

gulpfile.js

@@ -43,18 +43,18 @@ gulp.task('get-composer', function(callback) {
 });
 
 // Install Composer dependencies excluding development ones
-gulp.task('composer-install', ['get-composer'], function(callback) {
+gulp.task('composer-install', gulp.series('get-composer', function(callback) {
     exec(config.phpBin + ' composer.phar install --no-dev', function(error, stdout, stderr) {
         callback(error ? stderr : null);
     });
-});
+}));
 
 // Install all Composer dependencies
-gulp.task('composer-install-dev', ['get-composer'], function(callback) {
+gulp.task('composer-install-dev', gulp.series('get-composer', function(callback) {
     exec(config.phpBin + ' composer.phar install', function(error, stdout, stderr) {
         callback(error ? stderr : null);
     });
-});
+}));
 
 gulp.task('prepare-release', function() {
     var version = require('./package.json').version;
@@ -66,14 +66,12 @@ gulp.task('prepare-release', function() {
             .pipe(tar('slack-' + version + '.tar'))
             .pipe(gzip())
     )
-    .pipe(chmod(644))
+    .pipe(chmod(0644))
     .pipe(gulp.dest('release'));
 });
 
 // Builds and packs plugins sources
-gulp.task('default', ['composer-install','prepare-release'], function() {
-    // The "default" task is just an alias for "prepare-release" task.
-});
+gulp.task('default', gulp.series('composer-install','prepare-release'));
 
 /**
  * Returns files stream with the plugin sources.

package.json

@@ -2,12 +2,12 @@
   "version": "1.0.0",
   "devDependencies": {
     "event-stream": "~3.1.7",
-    "gulp": "^3.9.1",
-    "gulp-chmod": "~1.2.0",
+    "gulp": "^4.0.0",
+    "gulp-chmod": "~3.0.0",
     "gulp-composer": "*",
     "gulp-gzip": "~0.0.8",
     "gulp-rename": "~1.2.0",
-    "gulp-tar": "~1.3.1",
+    "gulp-tar": "~3.1.0",
     "gulp-util": "*",
     "gulp-zip": "~2.0.2"
   },
@@ -15,7 +15,7 @@
   "description": "Provides Slack notifications when initiate a chat",
   "main": "gulpfile.js",
   "dependencies": {
-    "gulp": "^3.9.1",
+    "gulp": "^4.0.0",
     "graceful-fs": "^4.1.11"
   },
   "scripts": {