A way to tell *why* backups are unhealthy

[hailwood]

Running php artisan backup:monitor with my backups totally over 5GB (my configured limit) I get the rather unhelpful message of

The backups on db-backups are considered unhealthy!

It would be great if we could something to tell us which check failed. E.g.

The backups on db-backups are considered unhealthy:

• Total size > 5GB

Or even as a bare minimum

The backups on db-backups are considered unhealthy (Health check: MaximumStorageInMegabytes)

[freekmurze]

Great idea, feel free to PR this! Be sure to include tests.