Update maintainers

Signed-off-by: David Laseca Perez <davidlaseca@eprosima.com>

CONTRIBUTING.md

@@ -6,6 +6,9 @@ the GitHub issues tracking system prior to any code development to coordinate
 with the micro-ROS development team early in the process. Coordinating up
 front helps to avoid frustration later on.
 
+Your contribution must be licensed under the Apache-2.0 license, the license
+used by this project.
+
 Any contribution that you make to this repository will
 be under the Apache 2 License, as dictated by that
 [license](http://www.apache.org/licenses/LICENSE-2.0.html):

package.xml

@@ -5,7 +5,7 @@
   <version>6.0.0</version>
   <description>Definitions for the ROS 2 msgs entities information used by micro-ROS to leverage its functionality to the same level as ROS 2, by means of a dedicated graph manager</description>
   <maintainer email="eugeniocollado@eprosima.com">Eugenio Collado</maintainer>
-  <maintainer email="carlosespinoza@eprosima.com">Carlos Espinoza</maintainer>
+  <maintainer email="davidlaseca@eprosima.com">David Laseca</maintainer>
   <license>Apache License 2.0</license>
 
   <buildtool_depend>ament_cmake</buildtool_depend>