Multinode TestFramework timeout handling

[cytadela8]

When a call to TestFramework timeouts, tests never terminate created nodes TestFramework.delete_all_nodes(). This causes leftover processes and leftover node files.

I think this issue is of low importance.

Workaround: call make killall to kill all elixir processes. rm -r apps/aecore/priv/test* to remove leftover files.