test_tiff_file_format: Added for testing the module nanshe_learner. This will address issues #118, #119, #120, #121, and #122.
__init__: Added test_nanshe_learner to __all__ and imported it as well.
test_nanshe_learner: Added a test for main from nanshe_learner. This partially addresses #122.
test_nanshe_learner: Added another test for main from nanshe_learner. This fixes #122.