config = reduce(argv, (acc, val, key) => {
  if (key === '_') return acc;
  return Object.assign(acc, { [key]: val });
}, config);

function reduce(obj, callback, initalValue) {
  return Object.keys(obj).reduce((acc, key) => {
    return callback(acc, obj[key], key);
  }, initalValue);
}

reduce({ test: 12 }, (acc, val, key) => Object.assign(acc, { [key]: val }), { test: 122 });