Update aws-sdk-kms to latest

[arothian]

Description

Updates aws-sdk-kms to resolve issues when using the previous pinned version and the latest s3 gem updated in #423

Issues Resolved

Check List

• [x] All tests pass. See https://github.com/chef-cookbooks/community_cookbook_documentation/blob/master/TESTING.MD
• [x] New functionality includes testing.
• [x] New functionality has been documented in the README if applicable
• [x] All commits have been signed for the Developer Certificate of Origin. See https://github.com/chef-cookbooks/community_cookbook_documentation/blob/master/CONTRIBUTING.MD

[arothian]

Thanks @tas50 . Any chance I could bother to push another patch release again?