修改npm install时的错误

app/src/main/index.dev.js

@@ -20,9 +20,9 @@ require('electron-debug')({ showDevTools: true })
 
 // Install `vue-devtools`
 require('electron').app.on('ready', () => {
-  let installExtension = require('electron-devtools-installer')
+  const installExtension = require('electron-devtools-installer')
   installExtension.default(installExtension.VUEJS_DEVTOOLS)
-    .then(() => {})
+    .then(() => ({}))
     .catch(err => {
       console.log('Unable to install `vue-devtools`: \n', err)
     })

app/src/main/index.js

@@ -7,7 +7,7 @@ const winURL = process.env.NODE_ENV === 'development'
   ? `http://localhost:${require('../../../config').port}`
   : `file://${__dirname}/index.html`
 
-function createWindow () {
+function createWindow() {
   /**
    * Initial window options
    */