py-botocore: updated to 1.8.15

1.8.15
api-change:appstream: Update appstream client to latest version

1.8.14
api-change:ses: Update ses client to latest version
enhancement:credentials: Moved the JSONFileCache from the CLI into botocore so that it can be used without importing from the cli.
api-change:apigateway: Update apigateway client to latest version

1.8.13
api-change:codedeploy: Update codedeploy client to latest version
bugfix:sagemaker-runtime: Renamed the runtime.sagemaker service to sagemaker-runtime to be more consistent with existing services. The old service name is now aliased to sagemaker-runtime to maintain backwards compatibility.
bugfix:Stubber: This change makes the error handling more verbose in the case where a stubbed method has been called, but the Stubber is not expecting a call.
api-change:workmail: Update workmail client to latest version

(adam)