code: function (auth, org, repo, ref, options, callback) {
      if (typeof options == 'function') {
        callback = options
        options  = {}
      }
  
      // a valid ref but we're not using this format
      ref = ref.replace(/^refs\//, '')
  
      var url = refsBaseUrl(org, repo, type) + '/' + ref
      ghutils.ghget(auth, url, options, callback)
    }
docs: no getTag API