title: ArrayField not recognized?
body: <p>I have the following error message:</p>
  
  <pre><code>AttributeError: 'module' object has no attribute 'ArrayField'
  </code></pre>
  
  <p>Here is the relevant code segment:</p>
  
  <pre><code>from __future__ import unicode_literals
  from django.db import models
  from django.contrib.postgres.fields import ArrayField
  
  class TypeStatistics(models.Model):
      bots_array = models.ArrayField(models.CharField(max_length=50), blank=True)
  </code></pre>
  
  <p>Any idea what can be causing this?</p>