Support AWS ECS Task Role credentials for S3 cache
https://github.com/minio/minio-go/releases in the v6.0.8 adds support for AWS ECS Task Role IAM credentials
It seems that simply by updating the minio-go version, this feature could be pulled in. Looking at https://gitlab.com/gitlab-org/gitlab-runner/blob/master/Gopkg.lock it seems that the version of that library is behind v6.0.8