Importing library leaves behind tmp directories

[nkrot]

This is a followup to the issue Running library leaves lots of temporary directories

Turns out tmp directories are created as soon as the library is imported and they are not deleted afterwards. Steps to reproduce:

1. start python3 in the terminal
2. type the command from DocumentFeatureSelection import interface
3. Observe 5 new empty directories created in tmp/
4. Press Ctrl-D to exit python session
5. Observe tmp directories are still there

Regards,