Fixes #167 (reproduced with gosns)
SNS: previous signature genaration msg.MD5OfMessageAttributes = common.GetMD5Hash("GoAws") caused failing of signature check in AWS SDK so could be simply deleted but I've added signature gen from gosqs.
SQS: add MD5OfMessageAttributes only if MessageAttributes not empty - according to logic of AWS SDK signature check failed if MessageAttributes filled and MD5OfMessageAttributes exists.
Fixes #167 (reproduced with gosns) SNS: previous signature genaration msg.MD5OfMessageAttributes = common.GetMD5Hash("GoAws") caused failing of signature check in AWS SDK so could be simply deleted but I've added signature gen from gosqs.
SQS: add MD5OfMessageAttributes only if MessageAttributes not empty - according to logic of AWS SDK signature check failed if MessageAttributes filled and MD5OfMessageAttributes exists.