Handle possible race condition during directory create

[randomir]

For all directory lookup operations when create=True, this gets executed in _get_folder():

homebase/homebase/homebase.py

Lines 429 to 430 in 482e917

	if create and not os.path.exists(final_path):
	os.makedirs(final_path)

Since directory existence check and create are not one atomic operation, it's possible directory gets created (by another thread or process running the same code) between the check and the create. When that happens, the other thread/process fails with FileExistsError.

The solution here is to set exist_ok=True when calling os.makedirs. I.e. the create op should be idempotent here.