Merge pull request #219 from peterbe/setup-py-resolve-gone-tests-require

`setup.py`: Resolve gone option `tests_require`

Author: hartwork

setup.py

@@ -28,8 +28,7 @@
     include_package_data=True,
     python_requires=">=3.9",
     install_requires=["packaging", "pip"],
-    tests_require=["pytest"],
-    extras_require={"dev": ["tox", "twine"]},
+    extras_require={"dev": ["tox", "twine"], "tests": ["pytest"]},
     classifiers=[
         "Intended Audience :: Developers",
         "Intended Audience :: System Administrators",