Convert manual config file to use Environment variables

[devinmatte]

The config file currently needs to be manually edited with config values. That is bad practice and reduces deployment options.
A good example may be how I do it in ScheduleMaker: https://github.com/devinmatte/schedulemaker/blob/master/inc/config.env.php

The goal is to pull from an environment variable, and in the absence of it being set, default to a default value