code: function getAuth (auth, url) {
    if (auth && auth.user && auth.pass) {
      return auth.user + ':' + auth.pass
    }
    return url.auth
  }
docs: Handle load response
  
  @callback loadCallback
  @param {?Error} error - whether there was an error retrieving configurations
  @param {module:Config~Config} config - configuration object instance
   
  Retrieve basic auth from options
  
  Priority:
  1. Defined in options
  2. Coded as basic auth in url
  
  @param {module:CloudConfigClient~Auth} auth - auth configuration.
  @param {URL} url - endpoint.
  @returns {string} basic auth.