Use the [built-in Rake Task available as part of the graphql-ruby
gem](https://github.com/rmosolgo/graphql-ruby/blob/master/lib/graphql/rake_task.rb)
in order to generate both
[IDL](https://www.prisma.io/blog/graphql-sdl-schema-definition-language-6755bcb9ce51)
and JSON schema files.

Also adds a rake task that checks to make sure the files are up-to-date
as well as runs the rake task in our CI