Feature: Use defaults for environment variables

I sort of discussed this with @joeyw on #377 but I wanted to display just how simple it is to get the tests to run with `./script/test`. 

This is a WIP and I will probably add to it so that user's can specify their own repository via an environment variable as well. We can then generalize the before/after blocks to use the specified environment variable for making requests and create a sensitive data filter for that with VCR. Ideally this will make future contributions less of a hassle for all.