* Twitch Webhook Registration Fix
This fixes the broken twitch webhook registration. I previously added
the `to_json` when I was switching to using HTTParty and working through
WebMock. I apparently forgot to test this manually however after and
relied on the specs that had some baked in bad assumptions.
This removes the `to_json` and configures the mocking properly in the
spec setup.
I tested locally that this can now succesfully register for webhooks
with Twitch!
* Fix Webhook verification digesting as well, hardcode the specs for durability
* Refactor to use shorter digest method
* Add cache buster lines from Bens branch
23ded947e3