Add release notes and set version to 0.5.0

Update version.py for 0.4.0

Update version.py

Changing version.py to match the release version

Update version.py to 0.2.0

Update version.py to 0.2.0-rc1

Update version.py for 0.2.0-rc0

Update release.md with 0.1.1 release.

PiperOrigin-RevId: 205810493

Merge pull request #2 from tensorflow/wip0.1

Add release notes and drop "-dev" suffix.