Inline some more kwargs into setup.py's setup() call.

- long_description can be defined right where it's used.
- It seems nicer to also define classifiers at the point of use
  (together with other "metadata"-like entries) rather than at the top
  of the file, far away from the point of use.

Author: anntzer

setup.py

@@ -73,21 +73,6 @@
     ]
 
 
-classifiers = [
-    'Development Status :: 5 - Production/Stable',
-    'Framework :: Matplotlib',
-    'Intended Audience :: Science/Research',
-    'Intended Audience :: Education',
-    'License :: OSI Approved :: Python Software Foundation License',
-    'Programming Language :: Python',
-    'Programming Language :: Python :: 3',
-    'Programming Language :: Python :: 3.6',
-    'Programming Language :: Python :: 3.7',
-    'Programming Language :: Python :: 3.8',
-    'Topic :: Scientific/Engineering :: Visualization',
-    ]
-
-
 class NoopTestCommand(TestCommand):
     def __init__(self, dist):
         print("Matplotlib does not support running tests with "
@@ -222,10 +207,6 @@ def run(self):
         with open('lib/matplotlib/mpl-data/matplotlibrc', 'w') as fd:
             fd.write(''.join(template_lines))
 
-    # Use Readme as long description
-    with open('README.rst', encoding='utf-8') as fd:
-        long_description = fd.read()
-
     # Finally, pass this all along to distutils to do the heavy lifting.
     setup(
         name="matplotlib",
@@ -242,10 +223,24 @@ def run(self):
             'Forum': 'https://discourse.matplotlib.org/',
             'Donate': 'https://numfocus.org/donate-to-matplotlib'
         },
-        long_description=long_description,
+        long_description=Path("README.rst").read_text(encoding="utf-8"),
         long_description_content_type="text/x-rst",
         license="PSF",
         platforms="any",
+        classifiers=[
+            'Development Status :: 5 - Production/Stable',
+            'Framework :: Matplotlib',
+            'Intended Audience :: Science/Research',
+            'Intended Audience :: Education',
+            'License :: OSI Approved :: Python Software Foundation License',
+            'Programming Language :: Python',
+            'Programming Language :: Python :: 3',
+            'Programming Language :: Python :: 3.6',
+            'Programming Language :: Python :: 3.7',
+            'Programming Language :: Python :: 3.8',
+            'Topic :: Scientific/Engineering :: Visualization',
+        ],
+
         package_dir={"": "lib"},
         packages=find_packages("lib"),
         namespace_packages=["mpl_toolkits"],
@@ -254,7 +249,6 @@ def run(self):
         # real extensions that can depend on numpy for the build.
         ext_modules=[Extension("", [])],
         package_data=package_data,
-        classifiers=classifiers,
 
         python_requires='>={}'.format('.'.join(str(n) for n in min_version)),
         setup_requires=[