升级使用最新的Electron 7.x以上版本，运行提示electron不存在，其实是因为electron install时候对应平台的可执行文件没有下载成功，错误提示如下：
(node:18000) UnhandledPromiseRejectionWarning: Error: EPERM: operation not permitted, lstat 'C:UsersJUNCHU~1AppDataLocalTempelectron-download-4VfCX9electron-v7.1.7-win32-x64.zip' (node:18000) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1) (node:18000) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code. npm WARN smartoffice@0.1.47 No repository field.
在官方的Git Issues找到了解决方案，就是修改使用另一个淘宝镜像地址。执行命令：
npm config set ELECTRON_MIRROR=https://cdn.npm.taobao.org/dist/electron/