title: AttributeError: class Home has no attribute 'as_view'
body: <p>I'm using <code>Flask Restful</code> and I want to render an <code>HTML file</code> on the root endpoint:</p>
  
  <pre><code>from flask_restful import Resource, Api
  app = Flask( __name__, static_url_path = '', static_folder = "docs" )
  api = Api(app, catch_all_404s=True)
  class Home():
      def get(self):
          return app.send_static_file( 'index.html' )
  api.add_resource(Home, '/')
  </code></pre>
  
  <p>When I run this code, I get this error:</p>
  
  <pre><code>    api.add_resource(Home, '/')
    File "/home/vagrant/.local/lib/python2.7/site-packages/flask_restful/__init__.py", line 404, in add_resource
      self._register_view(self.app, resource, *urls, **kwargs)
    File "/home/vagrant/.local/lib/python2.7/site-packages/flask_restful/__init__.py", line 444, in _register_view
      resource_func = self.output(resource.as_view(endpoint, *resource_class_args,
  AttributeError: class Home has no attribute 'as_view'
  </code></pre>
  
  <p>How to render a static file in <code>Flask Restful</code> ?</p>