title: Django 1.10 urls deprecation
body: <p>have some deprecation warning.
  Here is the problem:</p>
  
  <pre><code>RemovedInDjango110Warning: Support for string view arguments to url()
  is deprecated and will be removed in Django 1.10 
  (got django.views.static.serve). Pass the callable instead.
  'document_root': settings.MEDIA_ROOT,
  </code></pre>
  
  <p>Here is the urls:</p>
  
  <pre><code>urlpatterns = [
      url(r'^admin/', admin.site.urls),
      url(r'^ckeditor/', include('ckeditor_uploader.urls')),
      url(r'^media/(?P&lt;path&gt;.*)$', 'django.views.static.serve', {
              'document_root': settings.MEDIA_ROOT,
          }),
      url(r'^post/(\d+)$', post),
      url(r'^(\w+)$', category),
      url(r'^$', category),
  ]
  </code></pre>
  
  <p>How to fix it? Thanks for your time.</p>