the test scenario 'healthyHeadCheckWindow5' was causing index out of bounds errors.
the second range function in checkWindow was iterating over the incorrect slice of cids.
should be comparing latest items in slices first
watch if chain head changes in a given window of api polls
allows setting a threshold of how many times the chain head can remain
unchanged before failing health check
also can set interval for polling chain head
on failure, restarts systemd unit
