title: AttributeError: 'module' object has no attribute '__all__' when running django-maintenancemode
body: <p>I am running into this error when trying to run this middleware in django. <a href="https://github.com/shanx/django-maintenancemode" rel="nofollow noreferrer">https://github.com/shanx/django-maintenancemode</a></p>
  <p>It is returning a</p>
  <pre><code>AttributeError: 'module' object has no attribute '__all__'.
  </code></pre>
  <p>Is there something i am doing wrong? I am trying to test his out in my localhost environment within a virtualenv. I have placed the middleware into the settings file and this error is returned regardless of whether i have the mode set to true or false. I have placed a 503.html template within my templates folder which i want it to serve.</p>
  <h1>Traceback</h1>
  <pre><code>    Traceback (most recent call last):
    File &quot;C:\python27\Lib\wsgiref\handlers.py&quot;, line 85, in run
      self.result = application(self.environ, self.start_response)
    File &quot;C:\Users\Deep.C\.virtualenvs\dcwebdev\lib\site-packages\django\contrib\staticfiles\handlers.py&quot;, line 72, in __call__
      return self.application(environ, start_response)
    File &quot;C:\Users\Deep.C\.virtualenvs\dcwebdev\lib\site-packages\django\core\handlers\wsgi.py&quot;, line 236, in __call__
      self.load_middleware()
    File &quot;C:\Users\Deep.C\.virtualenvs\dcwebdev\lib\site-packages\django\core\handlers\base.py&quot;, line 51, in load_middleware
      mod = import_module(mw_module)
    File &quot;C:\Users\Deep.C\.virtualenvs\dcwebdev\lib\site-packages\django\utils\importlib.py&quot;, line 35, in import_module
      __import__(name)
    File &quot;C:\Users\Deep.C\.virtualenvs\dcwebdev\lib\site-packages\django_maintenancemode-0.9.3-py2.7.egg\maintenancemode\middleware.py&quot;, line 6, in &lt;module&gt;
      defaults.__all__.append('handler503')
  AttributeError: 'module' object has no attribute '__all__'
  [11/Jul/2013 14:57:57] &quot;GET / HTTP/1.1&quot; 500 59
  Traceback (most recent call last):
    File &quot;C:\python27\Lib\wsgiref\handlers.py&quot;, line 85, in run
      self.result = application(self.environ, self.start_response)
    File &quot;C:\Users\Deep.C\.virtualenvs\dcwebdev\lib\site-packages\django\contrib\staticfiles\handlers.py&quot;, line 72, in __call__
      return self.application(environ, start_response)
    File &quot;C:\Users\Deep.C\.virtualenvs\dcwebdev\lib\site-packages\django\core\handlers\wsgi.py&quot;, line 236, in __call__
      self.load_middleware()
    File &quot;C:\Users\Deep.C\.virtualenvs\dcwebdev\lib\site-packages\django\core\handlers\base.py&quot;, line 51, in load_middleware
      mod = import_module(mw_module)
    File &quot;C:\Users\Deep.C\.virtualenvs\dcwebdev\lib\site-packages\django\utils\importlib.py&quot;, line 35, in import_module
      __import__(name)
    File &quot;C:\Users\Deep.C\.virtualenvs\dcwebdev\lib\site-packages\django_maintenancemode-0.9.3-py2.7.egg\maintenancemode\middleware.py&quot;, line 6, in &lt;module&gt;
      defaults.__all__.append('handler503')
  AttributeError: 'module' object has no attribute '__all__'
  </code></pre>