replaced time.Sleep in main loop with ticker

Signed-off-by: Georgios Ntoutsos <gntouts@nubificus.co.uk>

cmd/verifier/main.go

@@ -101,7 +101,8 @@ func main() {
 	// 1. Fetch latest checkpoint and verify
 	// 2. If old checkpoint is present, verify consistency proof
 	// 3. Write latest checkpoint to file
-	for {
+	ticker := time.NewTicker(*interval)
+	for range ticker.C {
 		logInfo, err := rekor.GetLogInfo(context.Background(), rekorClient)
 		if err != nil {
 			log.Fatalf("Getting log info: %v", err)
@@ -185,6 +186,5 @@ func main() {
 		if *once {
 			return
 		}
-		time.Sleep(*interval)
 	}
 }