Set a Hapi response header for all requests
npm install hapi-set-header

hapi-set-header allows for globally setting a response header using an onPreResponse extension. Compatible with Boom responses.
The following example sets the Server header to Test Server
````
const Hapi = require('hapi');
const setHeader = requre('hapi-set-header');
const server = new Hapi.Server({});
setHeader(server, 'Server', 'Test Server');