Set _FOUND to trick ament_target_dependencies() for test (#396)
Set _FOUND to trick ament_target_dependencies() for test (#396)

* Set _FOUND to trick ament_target_dependencies() for test

Signed-off-by: Shane Loretz <7fde345e8e2e22c78a1570a4807e4629866dc7de@osrfoundation.org>

* Comment why setting _FOUND

Signed-off-by: Shane Loretz <7fde345e8e2e22c78a1570a4807e4629866dc7de@osrfoundation.org>

ros2/rosidl,ros2/rosidl,ros2/rosidl,ros2/rosidl