--log-file should create subdirectories

[nicoddemus]

If you provide a path with a subdirectory, which does not exist, it crashes with.
For example execute pytest --log-file=subtest/test.log produces something like this:
INTERNALERROR> FileNotFoundError: [Errno 2] No such file or directory: '/tmp/test/subtest/test.log'

Maybe someone want to add something like this

dirname = os.path.dirname(os.path.abspath(logfile))
if not os.path.isdir(dirname):
    os.makedirs(dirname)

However, there is the possibility to say that someone is not supposed to pass a directory path there.

Originally posted by @Hardy7cc in #7350 (comment)

[nicoddemus]

I agree, --junitxml works the same way. 👍

Would you like to take a stab at this @Hardy7cc?

[symonk]

Sorry ive been busy the past little while, I am doing some work in and around --log-file so I'm happy to build in support here also

[nicoddemus]

Thanks @symonk, and no need to be sorry, we all are busy at times!

Feel free to tackle this in #7350 if you like then. 👍

[Hardy7cc]

@nicoddemus Thanks for creating this new issue.
@symonk Thanks to take this up into your work around --log-file. I'm looking forward to see it ready, but take your time. I had this comment on my list for some days, so it does not hurry.