Update announcements.json

announcements.json

 [ 
-    {"id":23,"title":"周赛6月奖励","url":"http://www.duelcn.com/thread-60765-1-1.html","created_at":"2014-06-11T19:34:06+08:00","updated_at":"2014-07-1T19:34:06+08:00"}
+    {"id":23,"title":"竞赛联盟～暑假赛","url":"http://www.duelcn.com/forum.php?mod=viewthread&tid=60802&extra=","created_at":"2014-08-01T19:34:06+08:00","updated_at":"2014-08-11T19:34:06+08:00"},
     {"id":21,"title":"捐款地址更改为 my-card.in/donate ","url":"http://my-card.in/donate","created_at":"2014-05-06T10:34:06+08:00","updated_at":"2014-05-06T10:34:06+08:00"},
     {"id":18,"title":"游戏王竞赛联盟~周赛","url":"http://www.duelcn.com/thread-59882-1-1.html","created_at":"2013-12-01T18:55:06+08:00","updated_at":"2030-10-22T10:34:06+08:00"},
     {"id":4,"title":"QQ群: Mycard - 萌卡(225669895)","url":"http://qun.qzone.qq.com/group#!/225669895/home","created_at":"2013-02-19T18:12:07+08:00","updated_at":"2013-02-19T07:12:08+08:00"}