解决GitHub的raw.githubusercontent.com无法连接问题
由于国内一些网络防火墙的过滤，使得github部分网址并不能够访问。使用luarocks安装lua中的一些包文件的时候会经常遇到raw.githubusercontent.com源并不能访问。下面就这一问题进行解决：
在Linux系统中的hosts文件中
sudo nano /etc/hosts
添加以下内容即可
# GitHub Start
#yangxiangling begin
140.82.113.4 github.com
199.232.28.133 githubusercontent.com
199.232.28.133 raw.githubusercontent.com
192.30.253.112 github.com
192.30.253.113 github.com
192.30.253.119 gist.github.com
192.30.255.112 github.com git
151.101.185.194 github.global.ssl.fastly.net
151.101.88.249 github.global.ssl.fastly.net
151.101.100.133 assets-cdn.github.com
151.101.100.133 raw.githubusercontent.com
185.31.16.184 github.global.ssl.fastly.net
#yangxiangling end
52.74.223.119 github.com
192.30.253.119 gist.github.com
54.169.195.247 api.github.com
185.199.111.153 assets-cdn.github.com
151.101.76.133 raw.githubusercontent.com
151.101.108.133 user-images.githubusercontent.com
151.101.76.133 gist.githubusercontent.com
151.101.76.133 cloud.githubusercontent.com
151.101.76.133 camo.githubusercontent.com
151.101.76.133 avatars0.githubusercontent.com
151.101.76.133 avatars1.githubusercontent.com
151.101.76.133 avatars2.githubusercontent.com
151.101.76.133 avatars3.githubusercontent.com
151.101.76.133 avatars4.githubusercontent.com
151.101.76.133 avatars5.githubusercontent.com
151.101.76.133 avatars6.githubusercontent.com
151.101.76.133 avatars7.githubusercontent.com
151.101.76.133 avatars8.githubusercontent.com
# GitHub End
重新启动网络服务即可
/etc/init.d/network-manager restart