Simplify tool configuration

Remove options that re-specify the tools' defaults.

Author: jdufresne

setup.cfg

@@ -43,8 +43,8 @@ exclude =
     tests.*
 
 [flake8]
-exclude = .tox,venv,conf.py
-ignore = E203,W503,W601
+exclude = conf.py
+ignore = E203,W503
 max-line-length = 88
 
 [isort]
@@ -53,6 +53,4 @@ default_section = THIRDPARTY
 include_trailing_comma = true
 known_first_party = debug_toolbar
 multi_line_output = 3
-not_skip = __init__.py
-force_grid_wrap = 0
 line_length = 88