[ssh-agent]代理设置

参考：Adding your SSH key to the ssh-agent

生成新的ssh密钥之后，可以添加私钥到ssh-agent，这样之后拉取新的仓库或测试时就不再需要输入密码了

1. 启动ssh-agent

    $ eval "$(ssh-agent -s)"
    Agent pid 7804
   

2. 添加ssh私钥

    $ ssh-add ~/.ssh/github_id_rsa
    Enter passphrase for /home/zj/.ssh/github_id_rsa: 
    Identity added: /home/zj/.ssh/github_id_rsa (/home/zj/.ssh/github_id_rsa)