Feature: Pre-stage Github files

[nickmccollum]

Running an IO500 run in a closed environment that has no access to Github is difficult. It would be nice if the installer could pre-stage files in the install directory for users that want to run in an air gapped environment.

It it simple enough to change the installer script, commenting out the 'rm' and 'prepare.sh'/'configure' etc, then move the files over and comment out the github lines in the install script.