refactor: fix some coding style pointed by standard js

lib/finder-app.js

@@ -1,6 +1,5 @@
 const electron = require('electron')
 const app = electron.app
-const Menu = electron.Menu
 
 var finderWindow = null
 
@@ -8,11 +7,6 @@ app.on('ready', function () {
   if (process.platform === 'darwin') {
     app.dock.hide()
   }
-
-  // var template = require('./finder-menu')
-  // var menu = Menu.buildFromTemplate(template)
-  // Menu.setApplicationMenu(menu)
-
   finderWindow = require('./finder-window')
 })