Lint also async. Thanks to Akuket !

.eslintrc.json

@@ -6,7 +6,7 @@
     "browser": true
   },
   "parserOptions": {
-    "ecmaVersion": 6,
+    "ecmaVersion": 2017,
     "sourceType": "module",
     "ecmaFeatures": {
       "experimentalObjectRestSpread": true