500 error Cloudinary upload code.

Flask Image Upload

from flask import abort, request
from flask.views import MethodView
from flask.ext.login import login_required, current_user
from wtforms.fields import FileField
from wtforms import Form
from wtforms.validators import ValidationError
from werkzeug import secure_filename

import logging
import requests
import hashlib
import time

def _signature(keys, api_key):
  to_sign = "&".join(sorted([(k+"="+ str(v)) for k, v in keys.items() if v]))

  return hashlib.sha1(to_sign + api_key).hexdigest()

class Cloudinary(object):
  
  def __init__(self, app):
	self.config = app.config['CLOUDINARY_URL'].split(':')[2].split('@')
	self.address = 'http://api.cloudinary.com/v1_1/' + self.config[1] + '/image/upload'
	self.api_key = self.config[0]

  def upload_image(self, image, user):
    cloudinary_logging.info('User %s is uploading profile picture', user.get_id())

    keys = {'timestamp': int(time.time()), 'public_id': user.get_id()}
    keys['signature'] = _signature(keys, self.api_key)
    keys['api_key'] = self.api_key
    files = {'file': image.stream}
    response = requests.post(self.address, files=files, data=keys)
    response.raise_for_status()

    return response.json

class FileUploadField(FileField):
  '''Specialization copied from Flask-WTF'''

  @property
  def file(self):
    return request.files.get(self.name, None)

class ImageForm(Form):
  image = FileUploadField(u'image', validators = [ImageOnly()])

class ImageUploadView(MethodView):
  methods = ['POST']

  @login_required
  def post(self):
    upload_logging.info('User %s attempting to upload an image', current_user.get_id())
  	form = ImageForm(request.form)
  	try:
  	  if form.validate():
  	  	json_result = cloudinary.upload_image(form.image.file, current_user)
  	  	
  	  	return str(json_result) + "OMG PONIES, finish me"
  	  else:
  	  	upload_logging.warn('Uploaded image for user %s did not validate.', current_user.get_id())
  	  	
  	  	return abort(401)
  	except:
  	  upload_logging.exception('Failed to upload profile image for user %s', current_user.get_id())

  	  return abort(401)