Don't persist node and context between tests (#526)
Don't persist node and context between tests (#526)

Maybe fix https://github.com/ros2/rmw_cyclonedds/issues/117
Signed-off-by: Dan Rose <2591e5f46f28d303f9dc027d475a5c60d8dea17a@digilabs.io>
ros2/rclpy,ros2/rclpy