Add gcf packages to prep script.
Add gcf packages to prep script.

Add the gcf dependencies to the prep script. And be more specific
about what requires sudo so the script can be run by non-root users
and some commands can happen as a non-root user.

charliemeyer/geni-portal,charliemeyer/geni-portal,charliemeyer/geni-portal,tcmitchell/geni-portal,tcmitchell/geni-portal,charliemeyer/geni-portal,charliemeyer/geni-portal,tcmitchell/geni-portal,tcmitchell/geni-portal,tcmitchell/geni-portal