[tests] Update tests

tests/conftest.py

tests/segmentation/test_chasedb1.py

tests/segmentation/test_cxr8.py

tests/segmentation/test_drhagis.py

tests/segmentation/test_drionsdb.py

tests/segmentation/test_drishtigs1.py

tests/segmentation/test_drive.py

tests/segmentation/test_hrf.py

tests/segmentation/test_iostar.py

tests/segmentation/test_jsrt.py

tests/segmentation/test_montgomery.py

tests/segmentation/test_refuge.py

tests/segmentation/test_rimoner3.py

tests/segmentation/test_shenzhen.py

tests/segmentation/test_stare.py