code: function step(err, res) {
    if (!err && res && res.error) {
      console.log('ERR', res);
      err = res.error;
    }
    var nextStep = steps.shift();
    if (err && curStep !== 'delIndex') {
      console.log('failing on', curStep, err);
      console.trace();
      callback(err);
      return;
    }
    if (nextStep) {
      curStep = nextStep;
      var data = stepDefs[curStep].data;
      utils.doPostJson(stepDefs[curStep], data, step);
    } else {
      callback(err, res);
    }
  }
docs: check for an error, if no error do the next step, if no next step callback