Devel unit

Created by: mariojmdavid

fixes all errors and failures of unit_tests there where 2 commits affecting the udocker.py, which will have to be re-implemented together with new/changed unit_tests

• commit 5e6795b6
• commit ef39b0d7 (new option version) I think the last has to be implemented differently, or care must be taken in the respective unit_test