Fastify 2.6.0 release, implement custom serialization

Fastify 2.6.0 released, Fastify is a highly focused on Node.js Web framework provides the best possible experience with minimal overhead and powerful plug-in architecture for developers, and fast, and it's inspired by Hapi Express.

This updated version includes:

• feature: custom serialization
• This embodiment allows the use of a null option may
• Enhanced support for the Fluent Schema

Details View Update:

https://github.com/fastify/fastify/releases/tag/v2.6.0