Modify test suite code to be more generic

[slifty]

We wrote a test suite generation script for the CNN scrape util pipeline; the concept was that you could specify a url and it would create unit tests for each step of the pipeline for processing that URL.

This concept would also be useful to apply to other areas of the code (e.g. the twitter scrape pipeline, or even the scraper components themselves). It was written as a bit of an R&D concept, so not well organized or engineered. There is an issue for maybe breaking it into an npm module (#315) but in the mean time a smaller step would be to simply make the code more generic / put it into a util of its own.

[slifty]

We should also think about how this all compares to Jest snapshots. There isn't an exact overlap, but any refactoring should probably invoke snapshots where possible.