Fix vulnerabilities

package.json

@@ -60,7 +60,8 @@
     "style-loader": "^0.20.3",
     "stylelint": "^9.7.1",
     "url-loader": "^1.1.2",
-    "webpack": "^3.12.0",
-    "webpack-dev-server": "^2.11.3"
+    "webpack": "^4.16.1",
+    "webpack-cli": "^3.1.2",
+    "webpack-dev-server": "^3.1.10"
   }
 }