added delivery mode and content type json

client.go

@@ -17,6 +17,13 @@ var (
 	errShutdown      = errors.New("client is shutting down")
 )
 
+const (
+	DeliveryModeTransient  = amqp.Transient
+	DeliveryModePersistent = amqp.Persistent
+
+	ContentTypeJson = "application/json"
+)
+
 type Config struct {
 	ReconnectDelay time.Duration
 	ReInitDelay    time.Duration