kernels output fails if the kernel is creating output subfolders

To reproduce the issue:
- execute a kernel creating a directory and a file inside this directory
- execute kaggle kernel output my_kernel
It arises an "FileNotFoundError: [Errno 2] No such file or directory: "

To solve it, just add "os.makedirs(os.path.split(outfile)[0], exist_ok=True)" to "if force or self.download_needed(item, outfile, quiet):"

I'm creating a fork with the patch