'Update this key.
.. warning::
As of 20 June 2014, the API considers keys to be immutable.
This will soon begin to return MethodNotAllowed errors.
:param str title: (required), title of the key
:param str key: (required), text of the key file
:returns: bool'

@requires_auth
def update(self, title, key):

    json = None
    if (title and key):
        data = {u'title': title, u'key': key}
        json = self._json(self._patch(self._api, data=dumps(data)), 200)
    if json:
        self._update_attributes(json)
        return True
    return False
