POST a payload

def _add(app, endpoint, payload):
    '''
    POST a payload
    '''
    nb = _nb_obj(auth_required=True)
    try:
        return getattr(getattr(nb, app), endpoint).create(**payload)
    except RequestError as e:
        log.error('%s, %s, %s', e.req.request.headers, e.request_body, e.error)
        return False