S3 notification event

when creating a S3 event notification to SNS, the AWS throw out an error saying

turns out this is due to the access policy on SNS, which needs to be updated to point to the right S3 bucket.

After correcting the policy, it worked.

https://stackoverflow.com/questions/47215544/s3-bucket-lambda-event-unable-to-validate-the-following-destination-configurati/77425872#77425872