问题1：
git clone 时报错：Unable to negotiate with 207.97.227.239 port 22: no matching host key type found. Their offer: ssh-rsa
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
介绍这种情况的原因就是新的ssh客户端不支持ssh-rsa算法，要修改本地配置重新使用ssh-rsa算法。
具体做法：到当前用户目录下的.ssh文件中创建config文件（config没有后缀），使用记事本打开添加如下
添加以下配置
Host *
HostkeyAlgorithms +ssh-rsa
PubkeyAcceptedKeyTypes +ssh-rsa
问题2：
git clone 代码报Host key verification failed. fatal: Could not read from remote repository. Please make sure you have the correct access rights and the repository exists.
ssh 会验证对方服务器的 key。它没办法确认服务器出示的 key 是受信的，所以 key 是不是真的是你要连接的那个服务器的。没说「yes」所以 ssh 认为你不想继续连接，所以连接失败。
解决方法
请打开Git Bash，输入如下代码:
ssh -T git@github.com
如果提示“can't be established.”什么东西（如下代码），请不要管，直接按yes
The authenticity of host 'github.com (207.97.227.239)' can't be established. RSA key fingerprint is 16:27:ac:a5:76:28:2d:36:63:1b:56:4d:eb:df:a6:48. Are you sure you want to continue connecting (yes/no)?
然后提示输入密码（passphrase） 如果看到
You've successfully authenticated, but GitHub does not provide shell access
信息，就表示连接成功。
