[FLOC-1033] Configure acceptance nodes

Fixes FLOC-1033

I chose to split on colons because `PATH` is the environment variable list I am most familiar with and it works with colons.
> It seems like it would make sense to only check this once.

Do you mean not every test that is run but just when trial starts running tests?

> Also, it looks like this code is equivalent to checking if nodes[-1] is accessible.

Yes, unfortunately I'd been working on that when I said I was closing the PR but then pressed the wrong button :(