Create dir before creating log file

[JoostBuitink]

Fix the No such file or directory error when Wflow tries to write a log file in a (not yet) existing directory (see #209). Now, the directory is created before trying to create the log file.

[visr]

Thanks! we missed this, we do this for other output files as well.

Side note, seeing #209, do you think there is an added benefit of creating issues in cases like this, where you'll also directly work on the fix? I'd say issues are only useful to keep track of things that must be fixed later, or to discuss what is the problem or how to solve it.

[JoostBuitink]

I was doubting whether it was necessary to create an issue, but considered it might be useful to both flag that the issue has been found, and to keep track of the fixed issues for future releases (while writing this; I realize I should update the changelog as well). However, especially since the fix for this issue is rather straightforward and harmless, I agree it might be a bit "overkill".

[visr]

Yeah we can also use labels on PRs to indicate that they fix a bug. In the auto generated release notes, https://github.com/Deltares/Wflow.jl/releases/tag/v0.6.0, both issues and PRs are listed.

It's good to have this in the changelog, but it would have also been fine to leave out, since it's only meant for notable changes (for some definition of notable).

[JoostBuitink]

Thanks for the explanation - good to know. Will keep this in mind for future bugfixes!