Release 0.19.0

Major Features

• Add ffmpeg default thread options.
• Set deadline for ReadRows request in BigQuery.
• Allow setting the number of records fetched from kafka in KafkaDataset.

Thanks to our Contributors

This release contains contributions from many people:

Kota Yamaguchi, Vignesh Kothapalli, Vo Van Nghia, Yong Tang, emkornfield

We are also grateful to all who filed issues or helped resolve them, asked and
answered questions, and were part of inspiring discussions.