* Fix var precedence check to support python 3. * Run CI sanity tests using python 3.5. * Disable pylint non-iterator-returned test to pass on python 3.5.
* Fix pylint misplaced-bare-raise errors. * Fix pylint return-in-init error. * Fix pylint bad-format-character error. * Fix pylint too-many-format-args errors. * Fix pylint too-few-format-args errors. * Fix pylint truncated-format-string error.