title: django-image-cropping does not show cropping tool in the admin
body: <p>I'm trying to make django-image-cropping to work. I did the following steps:</p>
  
  <ol>
  <li><code>pip install django-image-cropping</code></li>
  <li><p><strong>settings.py</strong></p>
  
  <pre><code>INSTALLED_APPS = [
   [..]
  'easy_thumbnails',
  'image_cropping',
  ]
  [..]
  THUMBNAIL_DEBUG = True
  from easy_thumbnails.conf import Settings as thumbnail_settings
  THUMBNAIL_PROCESSORS = (
      'image_cropping.thumbnail_processors.crop_corners',
  ) + thumbnail_settings.THUMBNAIL_PROCESSORS
  </code></pre></li>
  <li><p><strong>models.py</strong></p>
  
  <pre><code>class AboutImg(models.Model):
      image = models.ImageField(blank=True, null=True,
                                upload_to='uploaded_images')
      cropping = ImageRatioField('image', '500x480')
  </code></pre></li>
  <li><p><strong>admin.py</strong></p>
  
  <pre><code>class MyModelAdmin(ImageCroppingMixin, admin.ModelAdmin):
      pass
  
  admin.site.register(AboutImg, MyModelAdmin)
  </code></pre></li>
  <li><p><strong>views.py</strong></p>
  
  <pre><code>def about(request):
      aboutimg = AboutImg.objects.order_by('pub_date').first()
      context = {'aboutimg': aboutimg}
      return render(request, 'about.html', context)`
  </code></pre></li>
  <li><p><strong>about.html</strong></p>
  
  <pre><code>{% load cropping %}
  
  &lt;img src="{% cropped_thumbnail aboutimg "cropping" %}"   
       class="img-responsive wooimg" alt="{{aboutimg.title}}"
       title="{{aboutimg.title}}" /&gt;
  </code></pre></li>
  </ol>
  
  <p>when I create a new istance of object <code>AboutImg</code> in the admin, the <code>cropping</code> field looks like that:
  <a href="https://i.stack.imgur.com/K5TJf.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/K5TJf.jpg" alt="cropping fails!"></a></p>
  
  <p>When I save the instance of <code>AboutImg</code> in the admin panel, I've also noticed that in my <code>upload_images/</code> folder two more images are created from the base image <code>05_2.jpg</code>:</p>
  
  <ul>
  <li>05_2_l3l0SL7.jpg</li>
  <li>05_2_l3l0SL7.jpg.1425x500_q85_detail_upscale.jpg</li>
  </ul>
  
  <p>and if I open the instance just created in the admin, now the base image is no more <code>05_2.jpg</code> but <code>05_2_l3l0SL7.jpg</code>.</p>
  
  <p><a href="https://i.stack.imgur.com/vEoCk.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/vEoCk.jpg" alt="enter image description here"></a></p>
  
  <p>I've checked all the stackoverflow questions about this subject, but none of the answers are ok with me.</p>
  
  <p>Thank you for your help.</p>
  
  <p>EDIT1: my env</p>
  
  <pre><code> `pip freeze &gt;  
    Django==1.8.3
    Pillow==4.0.0
    appdirs==1.4.0
    django-appconf==1.0.1
    django-image-cropping==1.0.4
    django-taggit==0.22.0
    easy-thumbnails==2.3
    olefile==0.44
    packaging==16.8
    pyparsing==2.1.10
    six==1.10.0
    wsgiref==0.1.2'
  </code></pre>
  
  <p>The JS console at /admin says</p>
  
  <p><a href="https://i.stack.imgur.com/2nOhF.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2nOhF.jpg" alt="jsconsole"></a></p>