Fix SNYK-GOLANG-GOPKGINYAMLV3-2841557

Hey all - I'm trying to solve https://security.snyk.io/vuln/SNYK-GOLANG-GOPKGINYAMLV3-2841557 which I'm getting via https://github.com/aws/aws-sdk-go. Usually, I'd put a PR in to bump the dependency in the tree but as it seems the link is testify which has been submodule here due to lock testify at `1.5.1` maintaining compatibility with Go <1.12 I'm not 100% on the next steps.

Does anyone with a better understanding of this package have any pointers on how to mitigate this vulnerability?