test ros2 iron support

Author: lreiher

.github/workflows/build.yml

@@ -11,6 +11,8 @@ jobs:
         ROS_DISTRO:
           - noetic
           - humble
+          - iron
+          - rolling
         ROS_REPO:
           - testing
           - main

README.md

@@ -5,7 +5,7 @@
   <img src="https://img.shields.io/github/license/ika-rwth-aachen/mqtt_client"/></a>
   <a href="https://github.com/ika-rwth-aachen/mqtt_client/actions/workflows/build.yml"><img src="https://github.com/ika-rwth-aachen/mqtt_client/actions/workflows/build.yml/badge.svg"/></a>
   <img src="https://img.shields.io/badge/ROS-noetic-blueviolet"/>
-  <img src="https://img.shields.io/badge/ROS 2-humble|rolling-blueviolet"/>
+  <img src="https://img.shields.io/badge/ROS 2-humble|iron|rolling-blueviolet"/>
   <a href="https://github.com/ika-rwth-aachen/mqtt_client"><img src="https://img.shields.io/github/stars/ika-rwth-aachen/mqtt_client?style=social"/></a>
 </p>