title: ImportError: No module named rest_framework.authtoken
body: <p>I'm using django rest-framework's, (DRF), token authentication in my project to create tokens when a user is created. Everything works great until I add this line from the DRF docs:</p>
  
  <pre><code>url(r'^api-token-auth/', 'rest_framework.authtoken.views.obtain_auth_token'),
  </code></pre>
  
  <p>to create an endpoint that returns the token for a user after correctly posting the username and password. </p>
  
  <p>It throws this error:</p>
  
  <pre><code>ImportError: No module named rest_framework.authtoken
  </code></pre>
  
  <p>This is strange because DRF is fine with out this line, so it must be included in my PYTHONPATH.</p>
  
  <p>I've also run <code>python manage.py syncdb</code> and the appropriate migrations. </p>
  
  <p>Any idea what could be wrong?</p>
  
  <p>Settings.py:</p>
  
  <pre><code>THIRD_PARTY_APPS = (
          'south',  # Database migration helpers:
          'crispy_forms',  # Form layouts
          'avatar',  # for user avatars
          'rest_framework', # for rest
          'django_rq', # for aysnc
          'rest_framework_swagger', # for exploring the api
          'rest_framework.authtoken',
      )
  INSTALLED_APPS = DJANGO_APPS + THIRD_PARTY_APPS + LOCAL_APPS
  </code></pre>
  
  <p>Full stack trace:    </p>
  
  <pre><code>Unhandled exception in thread started by &lt;function wrapper at 0x1046096e0&gt;
  Traceback (most recent call last):
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/django/utils/autoreload.py", line 93, in wrapper
      fn(*args, **kwargs)
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/django/core/management/commands/runserver.py", line 101, in inner_run
      self.validate(display_num_errors=True)
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/django/core/management/base.py", line 310, in validate
      num_errors = get_validation_errors(s, app)
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/django/core/management/validation.py", line 34, in get_validation_errors
      for (app_name, error) in get_app_errors().items():
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/django/db/models/loading.py", line 196, in get_app_errors
      self._populate()
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/django/db/models/loading.py", line 78, in _populate
      self.load_app(app_name)
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/django/db/models/loading.py", line 99, in load_app
      models = import_module('%s.models' % app_name)
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/django/utils/importlib.py", line 40, in import_module
      __import__(name)
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/debug_toolbar/models.py", line 63, in &lt;module&gt;
      patch_root_urlconf()
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/debug_toolbar/models.py", line 51, in patch_root_urlconf
      reverse('djdt:render_panel')
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/django/core/urlresolvers.py", line 480, in reverse
      app_list = resolver.app_dict[ns]
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/django/core/urlresolvers.py", line 310, in app_dict
      self._populate()
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/django/core/urlresolvers.py", line 273, in _populate
      for name in pattern.reverse_dict:
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/django/core/urlresolvers.py", line 296, in reverse_dict
      self._populate()
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/django/core/urlresolvers.py", line 285, in _populate
      lookups.appendlist(pattern.callback, (bits, p_pattern, pattern.default_args))
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/django/core/urlresolvers.py", line 229, in callback
      self._callback = get_callable(self._callback_str)
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/django/utils/functional.py", line 32, in wrapper
      result = func(*args)
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/django/core/urlresolvers.py", line 100, in get_callable
      not module_has_submodule(import_module(parentmod), submod)):
    File "/Users/admin/dev/ncla-web/env/lib/python2.7/site-packages/django/utils/importlib.py", line 40, in import_module
      __import__(name)
  ImportError: No module named rest_framework.authtoken
  </code></pre>