* Bump version without any changes, to upload to PyPI, which does not version overwriting.
0.2.1
* Downgrade required Python version from 3.5.3 to 3.5.2.
0.2.0
* Backwards compatible rewrite of internal code.
0.1.1
* Bug fix: could not convert nested dictionary with inner dictionary having a list as value, e.g. `{'a': {'b': [1, 2]}}`, because `num_rows` was derived from nested dictionary, but must be derived from flattened one.