Revert "Fix sudo for vagrant in ubuntu base box"

This reverts commit bc2fad9d11770a36739ecb2a82fc1207a426c47b.
Revert "Vagrant user needs to go in admin group on Ubuntu 12.*"

This reverts commit e54720a95342bace1958fe86877682aac6b7842e.
Fix passwordless sudo for vagrant user
Move all vagrant stuff to vagrant script