Added spec for main module matchers and helpers

Was writing some specs for the main matchers and stuff and thinking over the layout of the specs and what to do, and now that @jgraichen's stuff has added some specs, I thought I might as well add it now :+1: 

So, I'll probably change the formatting to match up with the existing specs, move the recipe in-line into the spec file etc.

Anyone got any major bugbears? @jgraichen @relistan @technicalpickles?

Thanks :smiley_cat: