#368: Correct tests around SystemExit context
#368 (closed): Testing exit() were not correctly written. Assertions were not tested, so tests would pass even if they shouldn't.
- correction of the form of tests (test_unit_tx.py ; test_crypto_tools.py)
- correction of the content of tests (test_unit_tx.py ; test_crypto_tools.py) Close #368 (closed).
Edited by Moul