Maybe make integration tests directly with shell testing frameworks, instead of python?
bin_tests.py currently implemented with python, and it's not very handy to edit and maintain. Some shell testing framework would be much better suited for this task.
https://code.google.com/p/shunit2/ and https://bmizerany.github.io/roundup/ are nice candidates.
Also: https://stackoverflow.com/questions/971945/unit-testing-for-shell-scripts