The authenticity of host 'github.com (52.74.223.119)' can't be established.
这里出现这个报错之后，如果直接回车的话，报错是ssh key的问题
当出现 The authenticity of host ‘github.com (52.74.223.119)’ can’t be established. 下列截图的这种
再询问Are you sure you want to continue connecting (yes/no/[fingerprint])? 应该输入yes 就正常了