Instead of defining the CliRunner value in each test, we use a fixture.
The CliRunner is also configured with stdout and stderr separated
because mixing them will pose problem if we use stderr for other
purposes in tests, e.g. to emit log messages from a forth-coming HTTP
server.
* Change all replica status from `running` to `streaming`
* Add an option to pytest to change the state back to `running`
* Also tests the output of the script
* Add a quick test script for live clusters
Previously, replica nodes were labeled with a `running` state. As a
result, our checks were based on nodes marked as `running` through
the `--running-[warning|critical]` options.
However, with the recent changes in Patroni 3.0.4, replica nodes now
carry a `streaming` state. This shift in terminology calls for an
adjustment in our approach. A new state, `healthy_member`, has been
introduced to encompass both `running` and `streaming` nodes.
Key Modifications:
* The existing `--running-[warning|critical]` option is now designated
as `--healthy-[warning|critical]`.
* Introduction of the `healthy_member` perfdata, which serves as the
reference point for the aforementioned options.
* Updates to documentation, help messages, and tests.
