Sagemaker-training

* [breaking change] Remove ``status_codes`` module and use ``six.moves.http_client`` instead
* [breaking change] Move ``UnsupportedFormatError`` from ``encoders`` module to ``errors`` module
* Return 4XX status codes for ``UnsupportedFormatError`` from default input/output handlers

* Allow for local modules to work with AWS SageMaker framework containers.
* Support for training outside of AWS SageMaker Training.

* Fix output_data_dir to reference an existing directory.
* Fix error message.
* Make pip install verbose.

* Fix error class for user script errors.
* Adding Readme.

* Improve logging
* Support for hyperparameters with JSON serialized and non serialized keys altogether
* Training Environment transforms to env vars
* Created beta framework entrypoint
* Filter SageMaker provided hyperparameters and user provided hyperparameters
* Script mode
* Cache module installation
* Support to requirements.txt
* Decoder/Encoder support for numpy, JSON, and CSV

* bug: Configuration: Change module names to string in __all__
* bug: Environment: handle hyperparameter injected by tuning jobs