Add test exposing bug in subtaxa_of_genus
Add test exposing bug in subtaxa_of_genus

The issue with `subtaxa_of` is a bug in `subtaxa_of_genus`.
So test `subtaxa_of_genus` separately.

MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer,MushroomObserver/mushroom-observer