Explicitly populate tuple with None (#711)
Explicitly populate tuple with None (#711)

I made a false assumption that tuple members which weren't specifically
populated would somehow default to 'None'. This change expclitly sets
the members to py::none().

Regression caused by a4d7292d356fbf078cd06c5de862d329658deabd

Signed-off-by: Scott K Logan <8c724d14625be4be480086a9212b212477a303ef@cottsay.net>
ros2/rclpy,ros2/rclpy