code: function(middleware, options) {
      if (this.server && this.server.auth) {
        this.server.auth(middleware, options);
      } else {
        throw new Error("vantage.auth is only available in Vantage.IO. Please use this (npm install vantage-io --save)");
      }
      return this;
    }
docs: Imports an authentication middleware
  module to replace the server's auth
  function, which is called when a remote
  instance of vantage connects.
  
  @param {Function} middleware
  @param {Object} options
  @return {Vantage}
  @api public