Iteration 0 - Node Basics
Our Linked List will ultimately be composed of individual nodes, so in this iteration we’ll start with building out these nodes.
Note that they are quite simple – a Node simply needs to have a slot for some data and a slot for a “next node”. Eventually this
next_node position will be what we use to link the multiple nodes together to form the list.
For this iteration, build a simple node class that can perform these functions:
> require "./lib/node" > node = Node.new("plop") > node.data => "plop" > node.next_node => nil