nvm与node安装

参考：

• 一文搞定NVM安装所有问题
• NVM UI
• 解决nodejs下载慢问题
  node_mirror: http://npmmirror.com/mirrors/node/
  npm_mirror: http://registry.npmmirror.com/mirrors/npm/
• 解决nvm list available报错问题
  Could not retrieve https://npm.taobao.org/mirrors/node/index.json.
  Get “https://npm.taobao.org/mirrors/node/index.json”: tls: failed to verify certificate: x509: certificate has expired or is not yet valid:
• Node.js Releases