Example of approaches to asynchronous code and testing in Node.js

In this example, we will show a callback based approach to making API calls, in addition to a a promise based approach and a generator based approach using 'co'

Each function will perform the same action of fetching a list of 'posts' from an API, and then for the first post, will fetch details of the user that created that post in a seperate API call.

The function will then return the name of the user and title of the post

This project demonstrates not only the differences in the application code with these approaches, but also the differences in test approach.