Jstorm 2.2.1 Released

Please refer to https://github.com/alibaba/jstorm/blob/master/history.md” for release notes

or https://github.com/alibaba/jstorm/blob/master/history_cn.mdfor Chinese release notes.

IMPORTANT: please refer to http://jstorm.io/QuickStart/Upgrade/UpgradeToJStorm221.html for upgrade guide.