Delete a cookie. Be sure to use the same `domain` and `path`
            parameters as used to create the cookie.

def delete_cookie(self, key, **kwargs):
        ''' Delete a cookie. Be sure to use the same `domain` and `path`
            parameters as used to create the cookie. '''
        kwargs['max_age'] = -1
        kwargs['expires'] = 0
        self.set_cookie(key, '', **kwargs)