update maintainers (#119)

* udpate maintainers
* add author

Signed-off-by: claireyywang <22240514+claireyywang@users.noreply.github.com>

rosidl_generator_py/package.xml

@@ -4,10 +4,12 @@
   <name>rosidl_generator_py</name>
   <version>0.9.3</version>
   <description>Generate the ROS interfaces in Python.</description>
-  <maintainer email="scott@openrobotics.org">Scott K Logan</maintainer>
+  <maintainer email="sloretz@openrobotics.org">Shane Loretz</maintainer>
+  <maintainer email="clairewang@openrobotics.org">Claire Wang</maintainer>
   <license>Apache License 2.0</license>
   <author>Esteve Fernandez</author>
   <author>Mikael Arguedas</author>
+  <author email="dthomas@osrfoundation.org">Dirk Thomas</author>	
 
   <build_depend>rosidl_runtime_c</build_depend>