Update pylint to 1.3.1

This is just to keep us on the upgrade treadmill. ([Changelog](https://bitbucket.org/logilab/pylint/src/9dce395369d32587f2c72c9f128523cfabbd1548/ChangeLog))
I generally find the codes confusing except when I'm trying to find documentation on a given pylint violation. If you feel it is worthless and no one else chimes in, then, so be it.