Add AsyncTripReader constructor with single consumer argument

src/main/java/de/stklcode/pubtrans/ura/reader/AsyncUraTripReader.java

@@ -46,6 +46,18 @@ public class AsyncUraTripReader implements AutoCloseable {
     private CompletableFuture<Void> future;
     private boolean cancelled;
 
+    /**
+     * Initialize trip reader.
+     *
+     * @param url      URL to read trips from.
+     * @param consumer Initial consumer.
+     */
+    public AsyncUraTripReader(URL url, Consumer<Trip> consumer) {
+        this.url = url;
+        this.consumers = new ArrayList<>();
+        this.consumers.add(consumer);
+    }
+
     /**
      * Initialize trip reader.
      *