Added complete example of ssh server without auth

```sh
ssh user@localhost -p 2022 ls -la # run command
ssh user@localhost -p 2022 # enter to shell
git clone ssh://user@localhost:2022/test.git # clone repository
```

Fix git clone/pull/push https://github.com/Scalingo/go-ssh-examples/issues/2
Based on https://gist.github.com/jpillora/b480fde82bff51a06238