Update for Twitch API

[barnumbirr]

Hey @PetterKraabol

kudos for maintaining this, you're doing God's work.
Do you have plans to update the library to be compatible with the GraphQL API so it can get chats from VODs?

Due to the old Helix API being deprecated, this feature currently doesn't work:

for comment in helix.video(318017128).comments:
    print(comment.commenter.display_name)

Cheers.