check pydot version at runtime
check pydot version at runtime

to avoid using an older version, because it causes failures in tests.
necozay/tulip-control,necozay/tulip-control,tulip-control/tulip-control,necozay/tulip-control,necozay/tulip-control,necozay/tulip-control,tulip-control/tulip-control,tulip-control/tulip-control,tulip-control/tulip-control