add authors

Author: zhangyangyu

AUTHORS

@@ -108,6 +108,7 @@ Xiangyu Hu <xiangyu.hu at outlook.com>
 Xiaobing Jiang <s7v7nislands at gmail.com>
 Xiuming Chen <cc at cxm.cc>
 Xuehong Chan <chanxuehong at gmail.com>
+Zhang Xiang <angwerzx at 126.com>
 Zhenye Xie <xiezhenye at gmail.com>
 Zhixin Wen <john.wenzhixin at gmail.com>
 Ziheng Lyu <zihenglv at gmail.com>
@@ -126,6 +127,7 @@ InfoSum Ltd.
 Keybase Inc.
 Multiplay Ltd.
 Percona LLC
+PingCAP Inc.
 Pivotal Inc.
 Stripe Inc.
 Zendesk Inc.