报错信息：
(base) name@myMacBook-Pro Downloads % ssh -T git@github.com
git@github.com: Permission denied (publickey).
解决方法：重新添加私钥
(base) name@myMacBook-Pro Downloads % ssh-add -K ~/.ssh/id_rsa_github
Identity added: /Users/username/.ssh/id_rsa_github (GitHub账号)
再次测试：
(base) name@myMacBook-Pro Downloads % ssh -T git@github.com
Hi my_username! You've successfully authenticated, but GitHub does not provide shell access.
