The cleanup command provided in the README doesn't work

[stevehs17]

According to the README, the following command will clean up the project after deploying it:
aws cloudformation delete-stack --stack-name tensorflow-inference-docker-lambda

When I run this, the stacks fail to be deleted because they include non-empty S3 buckets. In order to delete the stacks, I have to delete the contents of the buckets and then the buckets themselves.

It would be great to update the README with correct instructions for removing the project from AWS.