This is a small change that fixes an unused import and some line length

issues, cleaning things up in preparation for new work.
setup.cfg has been updated for the warnings we want to filter out,

based on our other projects. These include:

E121 - continuation line under-indented for hanging indent
E125 - continuation line with same indent as next logical line
E129 - visually indented line with same indent as next logical line
E241 - multiple spaces after ‘,’
W504 - line break after binary operator

Ran flake8. It no longer reported warnings.
Unit tests pass for Python 2.7-3.10.