1.git clone时遇到这个问题:
Failed to connect to github.com port 443: Timed out
可以使用这个命令解决：git config --global --unset http.proxy
2.git add 时遇到这个问题：
warning: LF will be replaced by CRLF in demo/demo.py. The file will have its original line endings in your working directory
可以使用这个命令解决：git config --global core.autocrlf true
