Log Message:
py-boto3: updated to 1.6.3

1.6.3
api-change:ssm: [botocore] Update ssm client to latest version
api-change:servicecatalog: [botocore] Update servicecatalog client to latest version
api-change:events: [botocore] Update events client to latest version
api-change:storagegateway: [botocore] Update storagegateway client to latest version
api-change:ec2: [botocore] Update ec2 client to latest version

1.6.2
api-change:application-autoscaling: [botocore] Update application-autoscaling \ 
client to latest version

1.6.1
api-change:ecr: [botocore] Update ecr client to latest version

1.6.0
enhancement:Stubber: [botocore] Added the ability to add items to response \ 
metadata with the stubber.
api-change:sts: [botocore] Update sts client to latest version
api-change:route53: [botocore] Update route53 client to latest version
feature:s3: [botocore] Default to virtual hosted addressing regardless of \ 
signature version