title: LoganSquare not including field name on generated Json
body: <p>I have a class <code>DbRecord</code></p>
  
  <pre><code>public class DbRecord {
  
  
      @JsonField(name="on_duties")
      List&lt;OnDutyElement&gt; onDuties;
  
      @JsonField(name = "date_time")
      DateTime dateTime;
  </code></pre>
  
  <p>When I try to serialize an object of this class, the LoganSquare doesn't include the dateTime field.</p>
  
  <p>Generated JSON: <code>{:"2015-12-21T11:32:17.503-05:00","on_duties":[{...everything normal from here</code></p>