Support for graphql-java 14

[lennyburdette]

The newest version of graphql-java was released January 16 and contains a few breaking changes. Supporting the new APIs doesn't look too complicated—to jumpstart things, here's a changeset with passing tests: https://github.com/apollographql/federation-jvm/compare/master...lennyburdette:graphql-java-14?expand=1

[paulbakker]

I should have created an issue as well, but I have an open PR to address this: #46

[glasser]

#41 also addresses this

[lennyburdette]

Closing in favor of #41 and #46