Not sure if I'm doing something wrong here but when I select an option from the potionshop it puts a potion of swiftness in my inventory.

Here's the link to the whole branch if you need more than the gist provides.

This is because there is a potionshop in the default configs that you are inadvertently inheriting. Oops, sorry!

Just add this to the top of the spell and it should be fine:

potionshop:
  inherit: false

Got it! Thanks Nathan.