Update dependency webpack-dev-server to v3.11.2

Author: renovate-bot

package.json

@@ -27,7 +27,7 @@
     "style-loader": "1.1.4",
     "webpack": "4.30.0",
     "webpack-cli": "3.3.12",
-    "webpack-dev-server": "3.3.1"
+    "webpack-dev-server": "3.11.2"
   },
   "scripts": {
     "lint": "eslint 'src/**/*.js'",