Update send.go in tutorial 1 for golang

Go1.5 for linux - need comma after amqp.Publishing

Author: AlexandrT

go/send.go

@@ -42,7 +42,7 @@ func main() {
 amqp.Publishing{
 ContentType: "text/plain",
 Body: []byte(body),
-})
+},)
 log.Printf(" [x] Sent %s", body)
 failOnError(err, "Failed to publish a message")
 }