Use nodes instead of node
Summary: `networkx 2.4+` replaced `node` attribute to `nodes` in graph object. This caused failures in `caffe2`'s' `topological_sort_traversal_longest_path` function which uses networkx library for topological sort.
Differential Revision: D27718857
fbshipit-source-id: 812fbb613946565d089cc84a20f3cdf7df046e19
Author
Avinash Nagaraj Bukkittu
