text: var MongoClient = require('mongodb').MongoClient;
  var url = "mongodb://localhost:27017/tracker";
  
  MongoClient.connect(url,{ useNewUrlParser: true }, function(err, mongoInstance) {
    if (err) throw err;
    console.log("DB created!");
    var dbo = mongoInstance.db("tracker");
    dbo.createCollection("todos", function(err, res) {
      if (err) throw err;
      console.log("Collection created!");
      mongoInstance.close();
    });
  });