Refactor routes from functions to classes

[christroutner]

This YouTube video shows a design pattern uses ES6 Classes that make writing unit tests much easier:

https://www.youtube.com/watch?v=lE3RYnchHps

The scope of this Issue is to refactor the libraries in the routes folder from functions to classes. This should not change any end-user functionality, just the structure of the code.

[christroutner]

I will create a feature branch, and implement this change for just the Insight Address library, to show off what the pattern would look like.