git的常见错误
github上传时出现error: src refspec master does not match any解决办法
http://www.jianshu.com/p/8d26730386f3
github上传时出现 error:ssh: connect to host github.com port 22: Operation timed out fatal: Could not read from remote repository.
http://stackoverflow.com/questions/35558649/github-error-ssh-connect-to-host-github-com-port-22-operation-timed-out-fat