Release 0.23.0

Major Features and Improvements

• Add promote for substructures.
• Add support for converting StructuredTensor to prensor.

Bug Fixes and Other Changes

• Depends on tensorflow>=2.3.0,<2.4
• Depends on tensorflow-metadata>=0.23,<0.24

Breaking Changes

• Drop snappy support for parquet dataset.

Deprecations

• Deprecating Py2 support.