No tests for Travis to run. You could add dependency-check && standard to the package.json

So I have added the tests, and solved most of the issues that were revealed.
However, I fear that by removing the offending lines some code will break, eg.
lib/constants.js:6:7: 'BASE_URL' is assigned a value but never used.
BASE_URL is never used in constants.js, but is used in retrieve.js like so: const { BASE_URL } = require('./constants.js')