ProcessPayload.__call__ doesn't fail if S3 upload fails

[jkeifer]

I saw an issue where the cirrus-geo process lambda was not given appropriate S3 permissions to allow uploading the payload to the S3 payloads bucket. However, the call to ProcessPayload.__call__ did not fail despite the S3 error returned, and the payload was ultimately dispatched to the specified workflow.

That __call__ needs to be audited to ensure it and all the functions it calls are not swallowing exceptions, and that upon hitting an exception it has the expected behavior of not processing that payload.

[jkeifer]

Here is the error I saw in the process logs: An error occurred (AccessDenied) when calling the PutObject operation: Access Denied.