Make tests in test_graph.cpp more reliable (#854)
Make tests in test_graph.cpp more reliable (#854)

* Make WaitForAllNodesAlive in test_graph.cpp more reliable, also fix leaks

Signed-off-by: Ivan Santiago Paunovic <f493a283e6aff807b3cc3b53203cbbb64f272da1@ekumenlabs.com>

* WaitForAllNodesAlive -> wait_for_all_nodes_alive

Signed-off-by: Ivan Santiago Paunovic <f493a283e6aff807b3cc3b53203cbbb64f272da1@ekumenlabs.com>
ros2/rcl,ros2/rcl