Config test: no error on missing directories

[ironsmile]

This may be an issue to specific handlers, but I will write it down here to make sure it does not get lost.

Lets consider this logger configuration:

    "logger": {
        "type": "ironsmile",
        "settings": {
            "log": "/var/log/nedomi/nedomi.log"
        }
    }

If the directory /var/log/nedomi/ does not exist, the ./nedomi -t will happily report "no errors". But then, trying to start the server with this config will fail.

This shouldn't be the case. In this particular example, the configuration test should have caught the missing directory and reported it as a configuration error.