Expose `Close()` and `Drain()`.

bus.go

@@ -25,6 +25,14 @@ func Connect(url string) (*Bus, error) {
 	return &Bus{NATS: encodedConn}, nil
 }
 
+func (bus *Bus) Close() {
+	bus.NATS.Close()
+}
+
+func (bus *Bus) Drain() error {
+	return bus.NATS.Drain()
+}
+
 func (bus *Bus) SendEmail(request *SendEmail) error {
 	return bus.Publish("email.outbound", request)
 }