AttributeError: 'ModelRoot' object has no attribute 'node'"

[licanwei]

unit test failed.
The reason is lib networkx rmoved G.node in version 2.4.
reference:
https://networkx.github.io/documentation/stable/release/release_2.4.html

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/696239

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/696239
Committed: https://git.openstack.org/cgit/openstack/watcher/commit/?id=4a269ba0395b1f83433f53d27a81662357334af2
Submitter: Zuul
Branch: master

commit 4a269ba0395b1f83433f53d27a81662357334af2
Author: licanwei <email address hidden>
Date: Wed Nov 27 15:25:25 2019 +0800

    Change self.node to self.nodes in model_root

    networkx removed G.node in version 2.4[1]
    G.node was replaced by G.nodes since version 2.0[2],
    and supports Python 2.7, 3.5, 3.6 and 3.7 from 2.2
    so the lower constraint version is 2.2.
    lib task_flow also invokes lib networkx,
    task_flow version is also needed to be updated.
    [1]: https://networkx.github.io/documentation/stable/release/release_2.4.html
    [2]: https://networkx.github.io/documentation/stable/release/release_2.0.html
    Change-Id: I268bcf57ec977bd8132a9f1573b28b681cb4ce1e
    Closes-Bug: #1854132