Fix linting

.eslintrc

@@ -1,11 +1,11 @@
 {
   "extends": "airbnb/base",
   "parserOptions": {
-    "ecmaVersion": 6,
+    "ecmaVersion": 2017,
     "sourceType": "module",
     "ecmaFeatures": {
       "experimentalObjectRestSpread": true
-    },
+    }
   },
   "env": {
     "node": true,
@@ -14,5 +14,6 @@
   "rules": {
     "quotes": [2, "single"],
     "no-underscore-dangle": [0],
+    "no-plusplus": ["error", { "allowForLoopAfterthoughts": true }]
   }
 }