In some rare cases it is possible for a row in Cassandra for
metrics to have no value for metric_id or created_at, though
they may still have updated_at and the other required columns.
This tool is for recreating the metric_id from the other required
columns.
An additional 'persister-check-missing-metric-id.py' tool is
provided which can be run to see if there are missing metric-id
values that need to be recreated.
Please see the README.rst for usage directions.
Story: 2005305
Task: 30611
Change-Id: I0593558407c8c773d728bbd035dde91310b59be3
(cherry picked from commit 09af9bff91e5a109d5bcd204f3647aa4fe023fe9)