Would be great if server just automatically restarted on version mismatch

```
There is a version mismatch between the spring client and the server.
You should restart the server and make sure to use the same version.

CLIENT: 1.6.4, SERVER: 1.6.3
```

There's nothing here for the client to do except call `spring stop` and then run the command again. 

Would be nice if we could do that work for them.
