Adding drone pipeline

.drone.yml

@@ -0,0 +1,18 @@
+kind: pipeline
+type: docker
+name: default
+
+steps:
+- name: Unit Test and lint
+  image: golang:1.23-bookworm
+  commands:
+  # - go build
+  - go mod download
+  - go test -race -v ./...
+  - go vet ./...
+  group: test-lint
+
+trigger:
+  event:
+    - pull_request
+    - push

cmd/publisher/main.go

@@ -22,7 +22,7 @@ func main() {
 		fmt.Printf("Received Message: %s from topic %s\n", msg.Payload(), msg.Topic())
 	})
 	options.OnConnect = func(c mqtt.Client) { fmt.Println("Connected to Broker") }
-	options.OnConnectionLost = func(c mqtt.Client, err error) { fmt.Println("Connection Lost: %v", err) }
+	options.OnConnectionLost = func(c mqtt.Client, err error) { fmt.Printf("Connection Lost: %v", err) }
 	client := mqtt.NewClient(options)
 	if token := client.Connect(); token.Wait() && token.Error() != nil {
 		panic(token.Error())