ensure setup.sh idempotence

[rogerthatdev]

Problem

setup.sh does not gracefully allow itself to be run twice.

Steps to Reproduce

Steps to reproduce the behavior:

1. Run setup.sh
2. Run it again

Expected behavior

There should be logic that allows setup.sh to run more than once without error.

An accompanying bash test would ensure this remains a requirement for all changes to setup script.

[ace-n]

Example fix as of December 13th, 2022