[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

setup.cfg

@@ -8,7 +8,7 @@ url = https://github.com/pre-commit/pre-commit
 author = Anthony Sottile
 author_email = asottile@umich.edu
 license = MIT
-license_file = LICENSE
+license_files = LICENSE
 classifiers =
     License :: OSI Approved :: MIT License
     Programming Language :: Python :: 3