Updated pylint
Updated pylint

Attempting to resolve Travis CI issue.

XCOM-315

edx/ecommerce,eduNEXT/edunext-ecommerce,edx/ecommerce,edx/ecommerce,janusnic/ecommerce,janusnic/ecommerce,mferenca/HMS-ecommerce,eduNEXT/edunext-ecommerce,janusnic/ecommerce,mferenca/HMS-ecommerce,edx/ecommerce,eduNEXT/edunext-ecommerce,mferenca/HMS-ecommerce,eduNEXT/edunext-ecommerce