Remove Old SSL Certificate(s) after new one is successfully applied

After awhile you'll have a bunch of old certificates in your list. No reason this shouldn't' be tidied up automatically.

It should delete the prior installed certificate right after the new certificate is successfully applied to the ELB.

This can be done with AWS CLI:
http://docs.aws.amazon.com/cli/latest/reference/iam/delete-server-certificate.html

Eg.

> aws iam delete-server-certificate --server-certificate-name "32192372168017-2016-10-18-www_mydomain_com-mydomain_com"