Test n-2 EKS k8s versions with IaC

[ntwkninja]

this is not direction, just a conversation starter

[RothAndrew]

This is really easy with the new Terratest setup. Let's talk. The hard work here will be actually keeping things compatible across various versions of kubernetes with logic in place that decides what to do based on which version of kubernetes is being used.

Bottom line: It's easy to set up the tests, but the tests will likely fail for all but the primary version of k8s until we add a bunch of logic.

[RothAndrew]

#93 is related to this. If and when we increase the number of valid kubernetes versions above 1, we'll need to start doing matrix testing (testing the same stuff multiple times but using different variables)