Update interfaces package.xml

Author: sgillen

greenwave_monitor_interfaces/package.xml

@@ -5,6 +5,8 @@
   <version>0.1.0</version>
   <description>Interfaces for the greenwave_monitor package</description>
   <maintainer email="[email protected]">Sean Gillen</maintainer>
+  <author email="[email protected]">Sean Gillen</author>
+  <author email="[email protected]">Ann Li</author>
   <license>Apache-2.0</license>
 
   <buildtool_depend>ament_cmake</buildtool_depend>
@@ -15,4 +17,4 @@
   <export>
     <build_type>ament_cmake</build_type>
   </export>
-</package>
+</package>