Run smoke test again Java Early Access Release

Run smoke test again JDK9 and JDK8 with `jjs` or `java`.

```
rake jdk8_ea
rake jdk9_ea
```

Currently JDK9 is not working.
Nice, it looks like RubyGems itself provides untar support (make sense considering the contents of a gem are tarballs).

https://gist.github.com/sinisterchipmunk/1335041