change urls in readme

README.md

@@ -2,11 +2,11 @@
 
 [![PyPi version]][PyPI] [![Build Status]][Travis CI]
 
-`Mirror` is an open source python application for mirror site (e.g. [mirror.bjtu.edu.cn](http://mirror.bjtu.edu.cn)) to sync files from upstreams (it uses [rsync](http://rsync.samba.org/) internally), it actually works like a [cron](http://en.wikipedia.org/wiki/Cron), but still has some differences. It has been served for mirror.bjtu.edu.cn with more than 40 rsync [tasks](http://mirror.bjtu.edu.cn/cn/update.html).
+`Mirror` is an open source python application for mirror site (e.g. [mirror.bjtu.edu.cn](https://mirror.bjtu.edu.cn)) to sync files from upstreams (it uses [rsync](http://rsync.samba.org/) internally), it actually works like a [cron](http://en.wikipedia.org/wiki/Cron), but still has some differences. It has been served for mirror.bjtu.edu.cn with more than 40 rsync [tasks](https://mirror.bjtu.edu.cn).
 
 You are welcome to send comments, patches and any others to [github](https://github.com/ideal/mirror/issues) or to [@idealities](http://twitter.com/idealities).
 
-Homepage: http://mirror.bjtu.edu.cn
+Homepage: https://mirror.bjtu.edu.cn
 
 Authors
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