Remove lint errors

default_app/main.js

@@ -91,7 +91,7 @@ app.once('ready', () => {
           }
         },
         {
-          role: 'togglefullscreen',
+          role: 'togglefullscreen'
         },
         {
           label: 'Toggle Developer Tools',

lib/browser/api/menu-item.js

@@ -5,7 +5,7 @@ const roles = require('./menu-item-roles')
 let nextCommandId = 0
 
 const MenuItem = function (options) {
-  const {app, Menu} = require('electron')
+  const {Menu} = require('electron')
 
   this.selector = options.selector
   this.type = options.type