Fixed a few things

Hey,  thought I'd try out your demo and take a look at snap.

Just a few things around environment variables, the version of packer you had was 0.6.1 which needed the new digital ocean api so I had to change the config json also the ruby script for deployment had typos in the env variable names.  Otherwise its awesome and thanks a lot. :D

I've also upgraded to packer 0.7.1.