Ubuntu Mate配置阿里源

Reason

Ubuntu的国外源经常访问不上，可以通过设置国内镜像源来提高访问速度。 sudo vim /etc/apt/sources.list 将文件内容修改为如下：

deb http://cn.archive.ubuntu.com/ubuntu/ willy main restricted universe multiverse
deb http://cn.archive.ubuntu.com/ubuntu/ willy-security main restricted universe multiverse
deb http://cn.archive.ubuntu.com/ubuntu/ willy-updates main restricted universe multiverse
deb http://cn.archive.ubuntu.com/ubuntu/ willy-backports main restricted universe multiverse
##测试版源
deb http://cn.archive.ubuntu.com/ubuntu/ willy-proposed main restricted universe multiverse
# 源码
deb-src http://cn.archive.ubuntu.com/ubuntu/ willy main restricted universe multiverse
deb-src http://cn.archive.ubuntu.com/ubuntu/ willy-security main restricted universe multiverse
deb-src http://cn.archive.ubuntu.com/ubuntu/ willy-updates main restricted universe multiverse
deb-src http://cn.archive.ubuntu.com/ubuntu/ willy-backports main restricted universe multiverse
##测试版源
deb-src http://cn.archive.ubuntu.com/ubuntu/ willy-proposed main restricted universe multiverse