title: Rails 4 + Postgres = Missing milliseconds in model timestamps
body: <p>I have timestamps in my model created with <code>t.timestamps</code> command in the migration.</p>
  
  <p>If I look in the database directly, the milliseconds are stored correctly. But when I fetch the object the milliseconds are not there.</p>
  
  <pre><code>Model.first.updated_at.iso8601(3)
   =&gt; "2013-09-28T13:43:58.000Z" 
  </code></pre>
  
  <p><strong>Why isn't the milliseconds fetched from the database?</strong></p>