The default log level ("WARN") means borgbackup does not output anything (and exits with a "0" return code) on success.
We'd like to have some more insight into long-running monthly backup repo checks and turn up the log level to "INFO" with this change.
See https://borgbackup.readthedocs.io/en/stable/usage/general.html#common-options .
Fixes #136 (closed).