Remove requirement on bob.db.iostar

bob/ip/binseg/configs/datasets/drivestarechasedb1hrf1024.py

...eg/configs/datasets/drivestarechasedb1hrf1024ssliostar.py

bob/ip/binseg/configs/datasets/iostarod.py

bob/ip/binseg/configs/datasets/iostarodtest.py

bob/ip/binseg/configs/datasets/iostarvessel.py

bob/ip/binseg/configs/datasets/iostarvessel1168.py

bob/ip/binseg/configs/datasets/iostarvessel544.py

bob/ip/binseg/configs/datasets/iostarvessel608.py

bob/ip/binseg/configs/datasets/iostarvessel960.py

bob/ip/binseg/configs/datasets/iostarvesseltest.py

bob/ip/binseg/data/hrf/__init__.py

bob/ip/binseg/data/hrf/test.py

bob/ip/binseg/data/iostar/__init__.py

bob/ip/binseg/data/iostar/default.json

bob/ip/binseg/data/iostar/optic-disc.json

bob/ip/binseg/data/iostar/test.py

bob/ip/binseg/data/iostar/vessel.json

bob/ip/binseg/engine/evaluator.py

bob/ip/binseg/engine/predictor.py

bob/ip/binseg/test/test_summary.py