Releases of tensorflow-io v0.13.0

[Yong Tang]

Hi All,

We are happy to announce the release of tensorflow-io v0.13.0, available through PyPI.org (`pip install tensorflow-io`)

The v0.13.0 release comes with many new features. Most notably python 3.8 support on all platforms, and a full spectrum of audio formats support, including encoding and decoding of WAV, Flac, Ogg (Vorbis), MP3, and MP4a under tfio.audio.

tensorflow-io v0.13.0 support python 3.5, 3.6, 3.7, and 3.8 on Linux/macOS/Windows.

All python wheel packages are available to be installed with:

```

pip install tensorflow-io[==version]

```

Please see more details from the release notes at the end of the email.

Thanks to everyone who contributed to and supported these releases!

# Release 0.13.0

## Major Features
* Add Python 3.8 support for Linux/macOS/Windows.
* Add Graph mode support for ArrowIOTensor.
* Add make_avro_dataset, parse_avro, and AvroRecordDataset
  in tfio.experimental.columnar for Avro file format support.
* Add GeoTIFF support in decode_tiff as an extension.
* Add Video Capture support for macOS and Linux.
* Add decode_nv12 and decode_yuy2 in tfio.experimental.image
  for colorspace conversion to RGB.
* Add decode_wav/encode_wav, decode_flac/encode_flac,
  decode_vorbis/encode_vorbis(ogg) decode_mp3/encode_mp3,
  decode_aac/encode_aac(mp4a) in tfio.audio for audio encoding and
  decoding support.

## Thanks to our Contributors

This release contains contributions from many people:

Aleksey Vlasenko, Ann Yan, Anthony Hsu, Bryan Cutler, Cheng Ren,
Florian Raudies, Keqiu Hu, Mark Daoust, Pei-Lun Liao, Pratik Dixit,
Yong Tang, Yuan Tang, Zou Xu, ashahab, marioecd

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