Bentoml

* Bugfix: `bentoml serve-gunicorn` command was broken in 0.6.0, which also breaks the API Server docker container. This is a minor release including a fix this issue https://github.com/bentoml/BentoML/issues/499

The biggest change in release 0.6.0 is revamped BentoML CLI, introducing new model/deployment management commands and new syntax for CLI inferencing.

1. New commands for managing your model repository:

> bentoml list

BENTO_SERVICE CREATED_AT APIS ARTIFACTS
IrisClassifier:20200123004254_CB6865 2020-01-23 08:43 predict::DataframeHandler model::SklearnModelArtifact
IrisClassifier:20200122010013_E0292E 2020-01-22 09:00 predict::DataframeHandler clf::PickleArtifact

> bentoml get IrisClassifier

> bentoml get IrisClassifier:20200123004254_CB6865

> bentoml get IrisClassifier:latest



2. Add support for using saved BentoServices by `name:version` tag instead of {saved_path}, here are some example commands:


> bentoml serve {saved_path}

> bentoml serve IrisClassifier:latest

> bentoml serve IrisClassifier:20200123004254_CB6865

* Fixed an issue with API server docker image build, where updating conda to newly released version causes the build to fail
* Documentation updates
* Removed the option to configure API endpoint output format by setting the HTTP header

* SageMaker model serving deployment improvements:
* Added num_of_gunicorn_workers_per_instance deployment option
* Gunicorn worker count can be set automatically based on host CPU now
* Improved testing for SageMaker model serving deployment

Minor bug fixes:

* AWS Lambda deployment - fix default namespace validation error (452)
* Tensorflow SavedModel artifact - use concrete_function instead of input auto-reshape (451)

* Minor bug fixes for AWS Lambda deployment creation and error handling