Various small fixes

Hi,

We've started using your excellent tool here at ITV to test our Vagrant boxes.

I made some mainly cosmetic changes which hopefully you agree with. It may be easier to review the pull request commit-by-commit as I've grouped the less-interesting whitespace changes together for example.

All the tests pass and I manually ran the modified gem against my own codebase as well as executing `serverspec-init` a few times to ensure I got the correct results.

Please let me know if you don't like the look of anything and I can change things back.

Ben