Pass code check with pylint=2.4.4 (#1012)

.github/workflows/code-check.yaml

.github/workflows/run-tests.yaml

.pylint

.travis.yml

Makefile

bin/mn

examples/bind.py

examples/cluster.py

examples/clusterSanity.py

examples/clustercli.py

examples/clusterdemo.py

examples/clusterperf.py

examples/consoles.py

examples/controllers.py

examples/controllers2.py

examples/controlnet.py

examples/cpu.py

examples/emptynet.py

examples/hwintf.py

examples/intfoptions.py