Add python dependency

package.xml

@@ -13,6 +13,8 @@
     <!-- The following tags are recommended by REP-136 -->
     <exec_depend condition="$ROS_VERSION == 1">catkin</exec_depend>
     <buildtool_depend>cmake</buildtool_depend>
+    <depend condition="$ROS_PYTHON_VERSION == 2">python</depend>
+    <depend condition="$ROS_PYTHON_VERSION == 3">python3</depend>
     <export>
         <build_type>cmake</build_type>
     </export>