Add {to,from}_numpy members as generated

Fix linter behaviour concerning issue 3449.

Change-Id: I7ad040419d3acb21244b4072d8ea70c2d0c596d2

pylintrc

@@ -295,7 +295,7 @@ ignored-classes=optparse.Values,thread._local,_thread._local
 # List of members which are set dynamically and missed by pylint inference
 # system, and so shouldn't trigger E1101 when accessed. Python regular
 # expressions are accepted.
-generated-members=
+generated-members=.+\.((to)|(from))_numpy
 
 # List of decorators that produce context managers, such as
 # contextlib.contextmanager. Add to this list to register other decorators that