System-test-clean-up doesn't bomb out when we get expected non-zero exit code
System-test-clean-up doesn't bomb out when we get expected non-zero exit code

Signed-off-by: Will Gant <d8a810e7448ab72c0faa0369ec09e9c977d142c5@engineerbetter.com>

EngineerBetter/concourse-up,EngineerBetter/concourse-up,EngineerBetter/concourse-up