title: Serialize django model with foreign key models
body: <p>How to serialize Django model in json format if I want to include foreign key models fields?</p>
  
  <p>If I have:</p>
  
  <pre><code>class Model1(models.Model):
      name=models.CharField()
      child=models.ForeignKey(Model2)
  
  class Mode2(models.Model):
      field1=models.CharField()
      field2=models.IntegerField()
  </code></pre>
  
  <p>I wanna include everything in json...</p>