title: Django isn't including the urls.py from an installed app
body: <p>I am getting the error below:</p>
  
  <pre><code>Caught NoReverseMatch while rendering: Reverse for 'satchless-checkout-prepare-order' with arguments '()' and keyword arguments '{}' not found.
  </code></pre>
  
  <p>But I have <code>satchless.contrib.checkout.common</code> in my installed apps.  Within <code>satchless.contrib.checkout.common</code> is a <code>urls.py</code> which contains:</p>
  
  <pre><code>from django.conf.urls.defaults import patterns, url
  
  from .views import confirmation, prepare_order, reactivate_order
  
  urlpatterns = patterns('',
      url(r'^prepare/$', prepare_order, {'typ': 'satchless_cart'},
          name='satchless-checkout-prepare-order'),
      url(r'^(?P&lt;order_token&gt;\w+)/confirmation/$', confirmation,
          name='satchless-checkout-confirmation'),
      url(r'^(?P&lt;order_token&gt;\w+)/reactivate/$', reactivate_order,
          name='satchless-checkout-reactivate-order'),
  )
  </code></pre>
  
  <p>Why am I not able to call <code>{% url satchless-checkout-prepare-order %}</code> from my template?</p>