[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.
Since the acceptance tests are destructive, I think that perhaps there should not be a default, in case somebody runs this on a machine with the tutorial nodes started for other reasons. (We could still provide a helper to start the tutorial nodes and then run this with the appropriate environment variable set).