Replace typography quotes (#1040)

fixes #1039

setup.cfg

@@ -13,7 +13,7 @@ addopts = --tb=native --doctest-modules
 exclude = .git,.idea,__pycache__,build,dist,.pytest_cache,*.egg-info
 
 # <http://pycodestyle.pycqa.org/en/latest/intro.html#error-codes>
-# E241 - multiple spaces after ‘,’
+# E241 - multiple spaces after ','
 # E501 - line too long
 # W503 - line break before binary operator
 ignore = E241,E501,W503