In sparse_binary_number add docstrings. Format similar to PEP-0257 examples https://www.python.org/dev/peps/pep-0257/#multi-line-docstrings.
In sparse_binary_number add docstrings. Format similar to PEP-0257 examples https://www.python.org/dev/peps/pep-0257/#multi-line-docstrings.

Add comment about number 1 is edge case.

beepscore/sparse_binary_number