Update laravel-mix version and fix default public path.

package.json

@@ -3,10 +3,10 @@
   "version": "1.0.0",
   "description": "Themosis framework boilerplate plugin.",
   "scripts": {
-    "dev": "NODE_ENV=development node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
-    "watch": "NODE_ENV=development node_modules/webpack/bin/webpack.js --watch --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
-    "hot": "NODE_ENV=development webpack-dev-server --inline --hot --config=node_modules/laravel-mix/setup/webpack.config.js",
-    "production": "NODE_ENV=production node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js"
+    "dev": "cross-env NODE_ENV=development node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
+    "watch": "cross-env NODE_ENV=development node_modules/webpack/bin/webpack.js --watch --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
+    "hot": "cross-env NODE_ENV=development webpack-dev-server --inline --hot --config=node_modules/laravel-mix/setup/webpack.config.js",
+    "production": "cross-env NODE_ENV=production node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js"
   },
   "author": "Themosis",
   "license": "GPL-2.0-or-later",
@@ -15,6 +15,7 @@
   },
   "homepage": "https://github.com/themosis/theme#readme",
   "devDependencies": {
-    "laravel-mix": "^3.0.0"
+    "cross-env": "^5.2.0",
+    "laravel-mix": "^4.0.0"
   }
 }

webpack.mix.js

@@ -10,6 +10,7 @@ let mix = require('laravel-mix');
  | file for your application, as well as bundling up your JS files.
  |
  */
+mix.setPublicPath('./');
 
 mix.js('assets/js/index.js', 'dist/').sass('assets/sass/style.scss', 'dist/');