Added shifter to npm install
Merge pull request #13 from blzaugg/patch-1

Add shifter dependency to README for npm -g install
Add stderr callback on every single cmd
Remove extra spaces
Determine specific node version
Autostamp ZIP releases with a comment based on the last commit
Use the next version of ZIP Archiver that will contain: https://github.com/eduardolundgren/node-zip-archiver/pull/3
Avoid output on terminal
version bump