code: function defaultify(type, validator, options) {
    return options && options.default ? defaults[type](validator, options) : validator;
  }
docs: Create a default based on a string identifier if one is provided.
  
  @param {String} type - types of defaults [date, uuid]
  @param {Joi} validator - the object being defaulted
  @param {DefaultSpecifierOptions} options - the options for creating the default
  @returns {Joi} - the new validator, possibly with a default