Major Features and Improvements
* Introduced TFXIO, the interface for
[Standardized TFX Inputs](https://github.com/tensorflow/community/blob/master/rfcs/20191017-tfx-standardized-inputs.md)
* Added the first implementation of TFXIO, for tf.Example on TFRecords.
Bug Fixes and Other Changes
* Added a test_util sub-package that contains a tool to discover and run all
the absltests in a dir (like python's unittest discovery).
* Requires `apache-beam>=2.17,<3`
* Requires `pyarrow>=0.15,<0.16`
* Requires `tensorflow>=1.15,<3`
* Requires `tensorflow-metadata>=0.21,<0.22`.
Breaking Changes
Deprecations