Distinguish between @steps that are for setup/teardown and actual test steps

[jernst]

We can rely on the Constellation to be cleaned up nicely -- if all nodes implement the cleanup. But it might not. Also, it may be advantageous to let individual tests clean up as well as possible after themselves.

We could use the pytest fixture idea / way of declaring, applied in a very specific way. Or add tags like @setup and @teardown.