This e2etest runs an init, plan, apply, destroy sequence against a test
configuration using the real template and null providers downloaded from
the official repository.
This test _does_ trample a bit on the scope of some already-existing
tests, but this is mainly just to check our assumptions about how
Terraform behaves to ensure that we can reach our main conclusion here:
that the main Terraform workflow commands interact correctly with each
other in real use and we can complete the full workflow.