title: Regex for s3 bucket name
body: <p>I'm trying to create an s3 bucket through cloudformation. I tried using regex ^([0-9a-z.-]){3,63}$, but it also accepts the patterns "..." and "---" which are invalid according to new s3 naming conventions. (Ref: <a href="https://docs.aws.amazon.com/AmazonS3/latest/dev/BucketRestrictions.html" rel="noreferrer">https://docs.aws.amazon.com/AmazonS3/latest/dev/BucketRestrictions.html</a>) Please help? </p>