CI / Hell Enabled

[inertia186]

As an automated continuous integration solution, I would like to ignore certain build failures, so I don't create false reports to developers.

Occasionally, BroadcastTest#test_can_retry_remote_node_error fails due to parallelized tests. This should not cause tests to fail unless HELL_ENABLED=true is set.

AC

• Require HELL_ENABLED=true to for tests like BroadcastTest#test_can_retry_remote_node_error to fail due to parallization.
• Document HELL_ENABLED=true.