DeprecationWarning: `open()` is deprecated in mongoose >= 4.11.0

When run this code on terminal "node server.js" then show this error.

This Error: DeprecationWarning: `open()` is deprecated in mongoose >= 4.11.0, use `openUri()` instead, or set the `useMongoClient` option if using `connect()` or `createConnection()`. See http://mongoosejs.com/docs/connections.html#use-mongo-client

