Update version to 0.9.0

Update version to 0.8.0

Update stable version to 0.7.3

Use tensorflow/serving Docker images

Update stable version to 0.7.1

Update version to 0.7.0

Update version to 0.6.0

Update README.md

Update stable version to 0.4.1

Update wrapping of key missing error

(cherry picked from commit bbb5a55)