Fixing #78 uncovered another error in the same view:
Traceback (most recent call last):
File "/vagrant/eggs/Django-1.8.3-py2.7.egg/django/core/handlers/base.py", line 132, in get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/vagrant/parts/django-sboard/sboard/views.py", line 70, in node_view
return view.validate() or view.render()
File "/vagrant/parts/django-sboard/sboard/nodes.py", line 567, in render
return json_response(self.node._doc)
File "/vagrant/parts/django-sboard/sboard/json.py", line 10, in json_response
return HttpResponse(content, mimetype='application/json')
File "/vagrant/eggs/Django-1.8.3-py2.7.egg/django/http/response.py", line 340, in __init__
super(HttpResponse, self).__init__(*args, **kwargs)
TypeError: __init__() got an unexpected keyword argument 'mimetype'
Fixing #78 uncovered another error in the same view: