ssh:“SSH keys are a way to identify trusted computers without involving passwords. You can generate an SSH key and add the public key to your GitHub account by following the procedures outlined in this section.”
1、首先先查看下github账户下的ssh list，删除过期或者有有危险的ssh. link here
2、如果账户中没有ssh,那么添加一个新的ssh.生成和添加一个ssh key，在此之前检查一下已经存在的ssh keys，如果没有public key 和private key ,那么就生成和添加一个ssh key，如果已经存在public key 和private key（or exampleid_rsa.pubandid_rsa），那么你需要“add your SSH key to the ssh-agent.”
3、然后将ssh key 添加到github账户中.
4、最后可以验证下ssh 连接
