Various suggestions for improvements

I am uncertain about the removal of /vbox, as I haven't figured out why you put it there.

And for vagrant, I don't know if you think it fit the purpose.  I just happen to want to use it together with VirtualBox for my purposes :)

As for the rastasheeb/ubuntu-sshd as base image, I just thought there were no reason to duplicate the same code that is part of so many images.

Let me know what you think.