Shift embedded nats to the default

broker/broker.go

@@ -38,13 +38,9 @@ type Subscriber interface {
 }
 
 var (
-	DefaultBroker Broker = newHttpBroker()
+	DefaultBroker Broker = NewBroker()
 )
 
-func NewBroker(opts ...Option) Broker {
-	return newHttpBroker(opts...)
-}
-
 func Init(opts ...Option) error {
 	return DefaultBroker.Init(opts...)
 }