build: Migrate from setup.py to pyproject.toml

Using `setup.py` is deprecated and the new recommanded way is to declare
a `pyproject.toml` file (see PEP 517 [^1]).

This commit proposes to use setuptools to achieve that, because
setuptools is already used by localstripe, is standard and referenced by
the official Python packaging documentation [^2], and seems to be the
most lightweight solution.

For some period, the `setup.py` file will be kept (although almost
empty), to allow old tools versions to keep working.

I have done the same migration for yamllint 7 months ago [^3] and it
appeared to work well.

[^1]: https://peps.python.org/pep-0517/
[^2]: https://packaging.python.org/en/latest/tutorials/installing-packages/
[^3]: adrienverge/yamllint#566

README.rst

@@ -242,7 +242,7 @@ To quickly build and run localstripe from source:
 
 .. code:: shell
 
- python setup.py sdist
+ python -m build
  pip install --user --upgrade dist/localstripe-*.tar.gz
  localstripe
 

pyproject.toml

@@ -0,0 +1,48 @@
+[project]
+name = "localstripe"
+description = """
+A fake but stateful Stripe server that you can run locally, for \
+testing purposes."""
+readme = {file = "README.rst", content-type = "text/x-rst"}
+requires-python = ">=3.8"
+license = {text = "GPL-3.0-or-later"}
+authors = [{name = "Adrien Vergé"}]
+classifiers = [
+    "Development Status :: 5 - Production/Stable",
+    "Intended Audience :: Developers",
+    "Topic :: Software Development",
+    "Topic :: Software Development :: Quality Assurance",
+    "Topic :: Software Development :: Testing",
+]
+dependencies = [
+    "aiohttp >=2.3.2",
+    "python-dateutil >=2.6.1",
+]
+dynamic = ["version"]
+
+[project.optional-dependencies]
+dev = [
+    "flake8",
+    "flake8-import-order",
+]
+
+[project.scripts]
+localstripe = "localstripe.server:start"
+
+[project.urls]
+homepage = "https://github.com/adrienverge/localstripe"
+repository = "https://github.com/adrienverge/localstripe"
+documentation = "https://github.com/adrienverge/localstripe"
+
+[build-system]
+build-backend = "setuptools.build_meta"
+requires = ["setuptools >= 61"]
+
+[tool.setuptools]
+packages = ["localstripe"]
+
+[tool.setuptools.package-data]
+localstripe = ["localstripe-v3.js"]
+
+[tool.setuptools.dynamic]
+version = {attr = "localstripe.__version__"}

setup.py

@@ -15,25 +15,6 @@
 
 from setuptools import setup
 
-from localstripe import __author__, __version__
-
-
-setup(
-    name='localstripe',
-    version=__version__,
-    author=__author__,
-    url='https://github.com/adrienverge/localstripe',
-    description=('A fake but stateful Stripe server that you can run locally, '
-                 'for testing purposes.'),
-
-    packages=['localstripe'],
-    entry_points={'console_scripts':
-                  ['localstripe=localstripe.server:start']},
-    package_data={
-        'localstripe': ['localstripe-v3.js'],
-    },
-    install_requires=[
-        'aiohttp >=2.3.2',
-        'python-dateutil >=2.6.1',
-    ],
-)
+# This is only kept for backward-compatibility with older versions that don't
+# support new packaging standards (e.g. PEP 517 or PEP 660):
+setup()