Add support for newer versions of graphql >= 2.1

[saida]

Hi,

Thanks for this great gem! We'd like to update our graphql gem to 2.1.3, but artemis depends on the older versions of graphql < 2.1. Do you have any plans to update this dependency?

[eapache-opslevel]

As of about 20 minutes ago there is finally an updated version of the graphql-client gem that supports newer graphql-ruby versions (https://github.com/github/graphql-client/pull/314#issuecomment-1908780304).

So this should be possible finally.

[saida]

That's great news, thank you!