listIssueEvents(issue, cb) {
      return this._request('GET', `/repos/${this.__repository}/issues/${issue}/events`, null, cb);
   }
List the events for an issue
@see https://developer.github.com/v3/issues/events/#list-events-for-an-issue
@param {number} issue - the issue to get events for
@param {Requestable.callback} [cb] - will receive the list of events
@return {Promise} - the promise for the http request