Task LSMR-8: attempt to switch to Python 3

SAS/LSMR/src/manage.py

-#!/usr/bin/python3
+#!/usr/bin/env -u PYTHONPATH python3
 import os
 import sys
 

SAS/LSMR/test/t_functional.py

-#!/usr/bin/python3
+#!/usr/bin/env -u PYTHONPATH python3
 
 # Copyright (C) 2018    ASTRON (Netherlands Institute for Radio Astronomy)
 # P.O. Box 2, 7990 AA Dwingeloo, The Netherlands

SAS/LSMR/test/t_lsmrapp_models.py

-#!/usr/bin/python3
+#!/usr/bin/env -u PYTHONPATH python3
 
 # Copyright (C) 2018    ASTRON (Netherlands Institute for Radio Astronomy)
 # P.O. Box 2, 7990 AA Dwingeloo, The Netherlands