v16.1.0-experimental-stream-defer.6 fails to work

[saihaj]

In v16.1.0-experimental-stream-defer.6 it doesn't provided defer and stream as part of specifiedDirectives https://github.com/graphql/graphql-js/blob/bc6b2e47512ee11c01eb5185d184990e743df736/src/type/directives.ts#L260-L269

You can check the CI job for contra/graphql-helix#220 where introspection will fail.

[robrichard]

@saihaj defer and stream will only be enabled if you pass enableDeferStream: true to GraphQLSchema. See additional discussion here: #12