http://www.voidcn.com/article/p-pdhiwqec-pt.html
https://help.github.com/cn/github/authenticating-to-github/connecting-to-github-with-ssh
▶ /usr/bin/ruby -e “$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)”
curl: (7) Failed to connect to raw.githubusercontent.com port 443: Operation timed out
Try to add your SSH key to Github before retry
https://help.github.com/articles/connecting-to-github-with-ssh/