Consider running graphql-over-http spec tests automatically
The GraphQL-over-HTTP working group made a test suite for the protocol. They run audits on various servers in their system, but it might be nice for us to use their tests directly in our test suite so we can find out if we break anything.

https://github.com/graphql/graphql-http/tree/master/implementations/apollo-server

As of right now we pass all the required tests but not all the SHOULD tests. Some of this is intentional (ie, the reason that they are SHOULDs is because the spec folks know that existing servers don't do what is SHOULDed and won't change for back-compat reasons) and others might now be. We should look into improving any unintentional spec warnings while we're at it.