I haven't had a chance to update the Arch base box in a while so using the Ubuntu one is far more likely to succeed for a new user (I did test that box recently as I traded my ErgoDox EZ to a friend and needed to reprogram it for him).
* clean trailing ws in Vagrantfile and util/avr_setup.sh
* replace triple quotes with heredoc.
Ruby doesn't have triple quotes; that's a Python thing. This was just being
parsed as multiple strings concatenated.
* add docker support to Vagrantfile
* make wants to find dfu-programmer in vagrant guest
