Updates required because of version changes

This is a great example, thank you so much - I couldn't have got my code working without it.
I had to change a few things in the code because of version changes.

1. meteor-node-stubs now uses stream-http instead of http-browserify
[https://github.com/meteor/node-stubs/issues/14](https://github.com/meteor/node-stubs/issues/14)

So the 'hack' fix to Response in the client code isn't needed, and in fact causes an error:

`Error: Cannot find module 'meteor-node-stubs/node_modules/http-browserify/lib/response'`

I had to update meteor-node-stubs because the version of stream-http it included used the Buffer polyfill which is no longer included in Meteor by default:

[https://github.com/meteor/meteor/pull/8327/commits/6f75eae1353b187e358ced331e5f8e3b91cda08d](https://github.com/meteor/meteor/pull/8327/commits/6f75eae1353b187e358ced331e5f8e3b91cda08d)

2. On the server, I had to change:

`import http from 'http';`

to:

`const http = require('http');`