properly handle exit codes in test script

tests/tests.sh

@@ -1,3 +1,5 @@
+set -e
+
 # To run these tests simply do 
 # ./tests.sh <license_key>
 
@@ -39,11 +41,12 @@ TotalSegmentator -i tests/reference_files/example_ct_sm.nii.gz -o tests/unittest
 pytest -v tests/test_end_to_end.py::test_end_to_end::test_lung_vessels
 
 # Test tissue types (without license)
-TotalSegmentator -i tests/reference_files/example_ct_sm.nii.gz -o tests/unittest_no_license.nii.gz -ta tissue_types -d cpu --ml
+#   (use "|| true" to not abort if this command returns exit code 1, which it should do)
+TotalSegmentator -i tests/reference_files/example_ct_sm.nii.gz -o tests/unittest_no_license.nii.gz -ta tissue_types -d cpu --ml || true
 pytest -v tests/test_end_to_end.py::test_end_to_end::test_tissue_types_wo_license
 
 # Test tissue types (wrong license)
-TotalSegmentator -i tests/reference_files/example_ct_sm.nii.gz -o tests/unittest_wrong_license.nii.gz -ta tissue_types -d cpu --ml -l aca_123456789
+TotalSegmentator -i tests/reference_files/example_ct_sm.nii.gz -o tests/unittest_wrong_license.nii.gz -ta tissue_types -d cpu --ml -l aca_123456789  || true
 pytest -v tests/test_end_to_end.py::test_end_to_end::test_tissue_types_wrong_license
 
 # Test tissue types (with license)