Allow additional Hapi route options to be passed

[robinvdvleuten]

This PR adds the functionality to pass additional route configuration options when using the plugin with Hapi. In my case for example, I needed to modify the auth options and wasn't be able to do at (unfortunately only CORS options can be passed at the moment).
It would make the current CORS option obsolete though (as you can see in the test case).

TODO:

• Update CHANGELOG.md with your change (include reference to issue & this PR)
• Make sure all of the significant new logic is covered by tests
• Rebase your changes on master so that they can be merged easily
• Make sure all tests and linter rules pass

[mikl]

Additional point in favour of this change – with the new cors setting in 2.0.0, it doesn’t appear possible to enable the Access-Control-Allow-Credentials header, which unfortunately makes it a pain to do local development, since create-react-app and similar usually run on a separate, hot-loading dev-server, and thus CORS is needed to talk to the GraphQL server.

[maxnachlinger]

I'm excited for this PR too :) @robinvdvleuten - it might be worth resolving the conflicts in your branch.

[robinvdvleuten]

@maxnachlinger good idea, did it immediately 👍

[robinvdvleuten]

It would be nice to have a look from one of the maintainers like @evans otherwise I keep fixing merge conflicts 😔

[evans]

@robinvdvleuten Really sorry about the delay! We'll merge and publish this right away. Thank you for the PR!

@maxnachlinger Thank you for taking a look as well