title: "Not authorized on ___ to execute command" with mLab + MongoDB ^3.0
body: <p>Connects without a hitch, but on <code>insert()</code> throws me this error.</p>
  
  <pre><code>var MongoClient = require('mongodb').MongoClient;
  const assert = require('assert');
  var url = 'mongodb://____:____@ds125565.mlab.com:25565/heroku_w268n9pj';
  
  MongoClient.connect(url, function(err, client) {
      assert.equal(null, err);
      db = client.db('temp');
      console.log("connected!");
      const collection = db.collection('temp');
      collection.insert([{
          something: please
      }
  });
  </code></pre>
  
  <p>I saw some other answers regarding mLab accounts and credentials, but I just created a new admin account for this. Frustrating because it was working previously with v2.3.</p>