Tests require missing images #64
Description
Several tests (for example, the one in test_estimate_alpha.py) fail because a required image is missing:
FAILED tests/test_estimate_alpha.py::test_alpha - FileNotFoundError: [Errno 2] No such file or directory: 'data/input_training_lowres/GT01.png'
FAILED tests/test_laplacians.py::test_laplacians - FileNotFoundError: [Errno 2] No such file or directory: 'data/input_training_lowres/GT01.png'
FAILED tests/test_lkm.py::test_lkm - FileNotFoundError: [Errno 2] No such file or directory: 'data/input_training_lowres/GT01.png'
FAILED tests/test_preconditioners.py::test_preconditioners - FileNotFoundError: [Errno 2] No such file or directory: 'data/input_training_lowres/GT01.png'
Could/should GT01.png be included?