Single Container View: truncate ID

Truncation Id inside of NewSingle() doesn't work.
It even doesn't have any effect.
Instead truncate the ID inside of NewMeta() call

container/main.go

@@ -34,7 +34,7 @@ func New(id string, collector collector.Collector, manager manager.Manager) *Con
 	return &Container{
 		Metrics:   models.NewMetrics(),
 		Id:        id,
-		Meta:      models.NewMeta("id", id),
+		Meta:      models.NewMeta("id", id[:12]),
 		Widgets:   widgets,
 		updater:   widgets,
 		collector: collector,