`model.save()` can fail with current `master`

[max3-2]

John,

currently model save can fail if the argument is a single string, e.g. model.save('test.mph') - this occurs due to

        # Possibly deduce format from file ending.
        if format is None:
            suffix = path.suffix if path else '.mph'

where path is str and thus has no suffix. I think either a clear specification that a pathlib.Path needs to be supplied (complicated) or a typecast in model.save() is needed.

Best

[john-hen]

That was an oversight in the latest commits, thanks for reporting. I'll fix that before the next release. We just need to coerce str to Path just like before.