Add ADR for AWS Sagemaker
Add ADR for AWS Sagemaker

This describes our decision to move from serving
Learning to Rank models with TensorFlow Serving
Docker containers, to a more robust, flexible,
and scalable approach by adopting AWS Sagemaker.

https://trello.com/c/yZQ9ft00/1450-write-an-adr-for-hosting-ltr-in-sagemaker

alphagov/rummager,alphagov/rummager