Automatic media deletion is broken

[smcoll]

Setting TWILIO_DELETE_MEDIA=True will cause the code to error out when handling a POST. A side effect is that only the first media object will be saved to Dropbox, and the text file will not.

Traceback (most recent call last):
  File "/app/.heroku/python/lib/python3.5/site-packages/flask/app.py", line 1988, in wsgi_app
    response = self.full_dispatch_request()
  File "/app/.heroku/python/lib/python3.5/site-packages/flask/app.py", line 1641, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/app/.heroku/python/lib/python3.5/site-packages/flask/app.py", line 1544, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/app/.heroku/python/lib/python3.5/site-packages/flask/_compat.py", line 33, in reraise
    raise value
  File "/app/.heroku/python/lib/python3.5/site-packages/flask/app.py", line 1639, in full_dispatch_request
    rv = self.dispatch_request()
  File "/app/.heroku/python/lib/python3.5/site-packages/flask/app.py", line 1625, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/app/run.py", line 50, in handle
    media_instance.delete()
  File "/app/.heroku/python/lib/python3.5/site-packages/twilio/rest/api/v2010/account/message/media.py", line 399, in delete
    return self._proxy.delete()
  File "/app/.heroku/python/lib/python3.5/site-packages/twilio/rest/api/v2010/account/message/media.py", line 252, in delete
    return self._version.delete('delete', self._uri)
   File "/app/.heroku/python/lib/python3.5/site-packages/twilio/version.py", line 88, in delete
    raise TwilioException('Unable to delete record')
twilio.exceptions.TwilioException: Unable to delete record