hofix - install privileges

[RobertLucian]

This should make the GoPiGo update/install with or without privileges the python package(s).

For updating/installing the python packages of the GoPiGo with su privileges the user will run:

# this
sudo sh -c "curl -kL dexterindustries.com/update_gopigo | bash"

# or this
curl -kL dexterindustries.com/update_gopigo > update_gopigo.sh
sudo bash update_gopigo.sh

For updating/installing the python packages of the GoPiGo without su privileges the user will run:

curl -kL dexterindustries.com/update_gopigo | bash

Further tests are still required. We need to make sure Raspbian For Robots still works fine, as-well as anything afferent and that DexterOS still works fine.