fix eslint for monster example (#1123)

example/monster/config.js

@@ -3,7 +3,7 @@
 //==========================================================================
 //vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
 //vvvvv Customization Starts vvvvv
-export default const config = {
+export const config = {
   db: { host: 'localhost', port: 27017, name: 'db' },
   redis:
   { default: { port: 6379 },
@@ -18,3 +18,4 @@ export default const config = {
 //^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 //==========================================================================
 
+export default config

package.json

@@ -85,7 +85,7 @@
     },
     "parser": "babel-eslint",
     "parserOptions": {
-      "ecmaVersion": 7,
+      "ecmaVersion": 8,
       "sourceType": "module",
       "ecmaFeatures": {
         "impliedStrict": true