title: Django admin breaks after upgrading to 1.8.1
body: <p>I upgraded from 1.7.3 to 1.8.1, and my admin is not working and the site is not loading because it fails while resolving paths.</p>
  
  <p>Exception:</p>
  
  <pre><code>Enable 'django.contrib.auth.context_processors.auth' in your TEMPLATES setting in order to use the admin application.
  </code></pre>
  
  <p>This is the stack trace:</p>
  
  <pre><code>Environment:
  
  
  Request Method: GET
  Request URL: 
  
  Django Version: 1.8.1
  Python Version: 2.7.8
  Installed Applications:
  ('django.contrib.admin',
   ..)
  Installed Middleware:
  ('django.contrib.sessions.middleware.SessionMiddleware',
   ..)
  
  
  Traceback:
  File "/app/.heroku/python/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
    119.                 resolver_match = resolver.resolve(request.path_info)
  File "/app/.heroku/python/lib/python2.7/site-packages/django/core/urlresolvers.py" in resolve
    366.             for pattern in self.url_patterns:
  File "/app/.heroku/python/lib/python2.7/site-packages/django/core/urlresolvers.py" in url_patterns
    402.         patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
  File "/app/.heroku/python/lib/python2.7/site-packages/django/core/urlresolvers.py" in urlconf_module
    396.             self._urlconf_module = import_module(self.urlconf_name)
  File "/app/.heroku/python/lib/python2.7/importlib/__init__.py" in import_module
    37.     __import__(name)
  File "/app/appname/urls.py" in &lt;module&gt;
    72.     url(r'^tarantino/', include(admin.site.urls)),
  File "/app/.heroku/python/lib/python2.7/site-packages/django/contrib/admin/sites.py" in urls
    291.         return self.get_urls(), 'admin', self.name
  File "/app/.heroku/python/lib/python2.7/site-packages/django/contrib/admin/sites.py" in get_urls
    250.             self.check_dependencies()
  File "/app/.heroku/python/lib/python2.7/site-packages/django/contrib/admin/sites.py" in check_dependencies
    194.                     "Enable 'django.contrib.auth.context_processors.auth' "
  
  Exception Type: ImproperlyConfigured at /
  Exception Value: Enable 'django.contrib.auth.context_processors.auth' in your TEMPLATES setting in order to use the admin application.
  </code></pre>
  
  <p>I do have <code>'django.contrib.auth.context_processors.auth</code> in my <code>TEMPLATE_CONTEXT_PROCESSORS</code> already so no sure why is this happening now?</p>