Migrate setup.py to declarative setup.cfg

Move all package metadata from setup.py to setup.cfg using
setuptools declarative config (via setuptools-py2cfg). setup.py
is reduced to a minimal shim.

- version: read dynamically via attr: unittest2pytest.__version__
- long_description: read from files via file: README.rst, CHANGELOG.rst
- All classifiers, entry_points, install_requires preserved exactly

Author: graingert

setup.cfg

@@ -1,3 +1,42 @@
+[metadata]
+name = unittest2pytest
+version = attr: unittest2pytest.__version__
+author = Hartmut Goebel
+author_email = h.goebel@crazy-compilers.com
+license = GPLv3+
+description = Convert unittest test-cases to pytest
+url = https://github.com/pytest-dev/unittest2pytest
+long_description = file: README.rst, CHANGELOG.rst
+long_description_content_type = text/x-rst
+classifiers =
+    Development Status :: 4 - Beta
+    Environment :: Console
+    Intended Audience :: Developers
+    License :: OSI Approved :: GNU General Public License v3 or later (GPLv3+)
+    Operating System :: OS Independent
+    Programming Language :: Python
+    Programming Language :: Python :: 3
+    Programming Language :: Python :: 3 :: Only
+    Programming Language :: Python :: 3.9
+    Programming Language :: Python :: 3.10
+    Programming Language :: Python :: 3.11
+    Programming Language :: Python :: 3.12
+    Programming Language :: Python :: 3.13
+    Programming Language :: Python :: 3.14
+    Programming Language :: Python :: 3.15
+    Topic :: Software Development
+    Topic :: Utilities
+
+[options]
+packages = unittest2pytest, unittest2pytest.fixes
+zip_safe = False
+install_requires = fissix
+python_requires = >=3.9
+
+[options.entry_points]
+console_scripts =
+    unittest2pytest = unittest2pytest.__main__:main
+
 [zest.releaser]
 python-file-with-version = unittest2pytest/__init__.py
 push-changes = no

setup.py

@@ -1,85 +1,3 @@
-#!/usr/bin/env python
-#
-# Copyright 2015-2019 by Hartmut Goebel <h.goebel@crazy-compilers.com>
-#
-# This file is part of unittest2pytest.
-#
-# unittest2pytest is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful, but
-# WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-# General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program. If not, see <http://www.gnu.org/licenses/>.
-#
-from pathlib import Path
-
 from setuptools import setup
-import re
-
-
-this_dir = Path(__file__).parent
-
-def get_version(filename):
-    """
-    Return package version as listed in `__version__` in `filename`.
-    """
-    init_py = this_dir.joinpath(filename).read_text(encoding="utf-8")
-    return re.search("__version__ = ['\"]([^'\"]+)['\"]", init_py).group(1)
-
-
-version = get_version('unittest2pytest/__init__.py')
-
-
-def read(filename):
-    return this_dir.joinpath(filename).read_text(encoding='utf-8')
-
-
-long_description = '\n\n'.join([read('README.rst'),
-                                read('CHANGELOG.rst')])
-
 
-setup(
-    name="unittest2pytest",
-    license='GPLv3+',
-    version=version,
-    description="Convert unittest test-cases to pytest",
-    long_description=long_description,
-    long_description_content_type="text/x-rst",
-    author="Hartmut Goebel",
-    author_email="h.goebel@crazy-compilers.com",
-    url="https://github.com/pytest-dev/unittest2pytest",
-    packages=["unittest2pytest", "unittest2pytest.fixes"],
-    entry_points={
-        'console_scripts': [
-            'unittest2pytest = unittest2pytest.__main__:main',
-        ],
-    },
-    classifiers=[
-        "Development Status :: 4 - Beta",
-        "Environment :: Console",
-        "Intended Audience :: Developers",
-        "License :: OSI Approved :: GNU General Public License v3 or later (GPLv3+)",
-        "Operating System :: OS Independent",
-        "Programming Language :: Python",
-        "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3 :: Only",
-        "Programming Language :: Python :: 3.9",
-        "Programming Language :: Python :: 3.10",
-        "Programming Language :: Python :: 3.11",
-        "Programming Language :: Python :: 3.12",
-        "Programming Language :: Python :: 3.13",
-        "Programming Language :: Python :: 3.14",
-        "Programming Language :: Python :: 3.15",
-        "Topic :: Software Development",
-        "Topic :: Utilities",
-    ],
-    install_requires=["fissix"],
-    python_requires=">=3.9",
-    zip_safe=False
-)
+setup()