Support for Fastify 2

[Crecket]

I see someone already made this library compatible with #5 for Fastify v2 but I don't see a new version. Do you still need to release this?

[gendronb]

@lolo32,

Has #5 been published to npm?

[pearofducks]

Just a heads up that I've made a new plugin for Fastify 3 here - https://github.com/pearofducks/fastify-request-timing