Support fastify

Hi everyone! In respect to your contributing guidelines, I wanted to see if a consensus needed to be reached. Fastify has been picking up traction with 3k stars and 7k downloads this month. I'm using the fastify-apollo plugin I made in production and am loving it. To advocate, it's easy to implement routing and separate concerns outside of the graphql endpoint. Also fastify/fastify#302 brought up the issue of not enough visibility.

I got a good response in the Slack channel submit a PR but wanted to do my due diligence first.

[martijnwalraven]

Thanks for opening an issue! We'd be happy to include aapollo-server-fastify package based on fastify-apollo.

My only concern would be that we'd really prefer all packages in this repo to be written in TypeScript, because that makes testing and releasing things together a lot easier.

My only concern would be that we'd really prefer all packages in this repo to be written in TypeScript, because that makes testing and releasing things together a lot easier.

Not a problem

I am also thinking not to include fastify-plugin in this iteration. Since each instance of fastify is scoped, the plugin just overrides that. But routes are not scoped...so it doesn't matter and one less dependency.

[lednhatkhanh]

It's really a good idea, I search for fastify and apollo integration right after I tried it for the first time. Hope that we can have an Apollo + fastify package soon!