New features and bug fixes, released on 6 January 2020.
Important:
* Python 2.7 and 3.5 support has been dropped.
* Python 3.8 support has been added into Travis CI.
* A change to the defaults for `Table.nonzero_counts` was performed such that the default now is to count the number of nonzero features. See [issue #685](https://github.com/biocore/biom-format/issues/685)
* We now require a SciPy >= 1.3.1. See [issue #816](https://github.com/biocore/biom-format/issues/816)
New Features:
* The detailed report is no longer part of the table validator. See [issue #378](https://github.com/biocore/biom-format/issues/378).
*`load_table` now accepts open file handles. See [issue #481](https://github.com/biocore/biom-format/issues/481).
*`biom export-metadata` has been added to export metadata as TSV. See [issue #820](https://github.com/biocore/biom-format/issues/820).
Bug fixes:
*`Table.to_dataframe(dense=False)` does now correctly produce sparse data frames (and not accidentally dense ones as before). See [issue #808](https://github.com/biocore/biom-format/issues/808).
* Order of error evaluations was unstable in Python versions without implicit `OrderedDict`. See [issue #813](https://github.com/biocore/biom-format/issues/813). Thanks @gwarmstrong for identifying this bug.
*`Table._extract_data_from_tsv` would fail if taxonomy was provided, and if the first row had the empty string for taxonomy. See [issue #827](https://github.com/biocore/biom-format/issues/827). Thanks @KasperSkytte for identifying this bug.