message: most of vtl working for message attribute, just need to get stringvalue set
diff: @@ -91,12 +91,16 @@ export class TheBigFanStack extends cdk.Stack {
  requestParameters: {
  'integration.request.header.Content-Type': "'application/json'",
  'integration.request.querystring.Version': "'2010-03-31'",
  - 'integration.request.querystring.TargetArn': "'"+topic.topicArn+"'"
  + 'integration.request.querystring.TargetArn': "'"+topic.topicArn+"'",
  + 'integration.request.querystring.MessageAttributes.entry.1.Name': "'status'",
  + 'integration.request.querystring.MessageAttributes.entry.1.Value.DataType': "'String'"
  },
  requestTemplates: {
  // This is the VTL to transform our incoming request to post to our SNS topic
  // Check: https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-mapping-template-reference.html
  - 'application/json': "#set($context.requestOverride.querystring.Message = \"$input.path('$.message')\")"
  + 'application/json': "#set($context.requestOverride.querystring.Message = \"$input.path('$.message')\") \n"+
  + "## Add in value for Message Attribute \n" +
  + "#set($context.requestOverride.querystring.MessageAttributes.entry.1.Value.StringValue = \"created\")"
  },
  passthroughBehavior: apigw.PassthroughBehavior.NEVER,
  integrationResponses: [
  