Added some pylint disables to handle six imports

Some of the `import __future__ from absolute_import`'s were confusing
pylint on Jenkins. I checked that the version of six on Jenkins is
up-to-date-enough to actually import the modules that are now disabled,
and they all worked as of at least `six 1.5.2`.

This doesn't fix all of the pylint errors, but it's a good start.