setup: adapt setup.[cfg|py] for Py3.6+

Co-authored-by: dgw <[email protected]>

setup.cfg

@@ -16,17 +16,14 @@ classifiers =
     License :: Eiffel Forum License (EFL)
     License :: OSI Approved :: Eiffel Forum License
     Operating System :: POSIX :: Linux
-    Programming Language :: Python :: 2.7
-    Programming Language :: Python :: 3.3
-    Programming Language :: Python :: 3.4
-    Programming Language :: Python :: 3.5
     Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
+    Programming Language :: Python :: 3.9
     Topic :: Communications :: Chat :: Internet Relay Chat
 
 [options]
-python_requires = >=2.7, !=3.0.*, !=3.1.*, !=3.2.*, <4
+python_requires = >=3.6, <4
 packages = find:
 zip_safe = false
 

setup.py

@@ -34,16 +34,17 @@
 
 # We check Python's version ourselves in case someone installed Sopel on an
 # old version of pip (<9.0.0), which doesn't know about `python_requires`.
-if sys.version_info < (2, 7) or (
-    sys.version_info.major >= 3 and sys.version_info < (3, 3)
-):
+if sys.version_info < (3, 6):
     # Maybe not the best way to do this, but this question is tiring.
-    raise ImportError('Sopel requires Python 2.7+ or 3.3+.')
-# Py2 EOL: https://www.python.org/dev/peps/pep-0373/#maintenance-releases
-if sys.version_info.major == 2:
+    raise ImportError('Sopel requires Python 3.6+.')
+
+# Py3.6 EOL: https://www.python.org/dev/peps/pep-0494/#lifespan
+if sys.version_info < (3, 7):
+    # TODO check this warning before releasing Sopel 8.0
     print(
-        'Warning: Python 2.x has reached end of life and will receive '
-        'no further updates. Sopel 8.0 will drop support for it.',
+        'Warning: Python 3.6 will reach end of life by the end of 2021 '
+        'and will receive no further updates. '
+        'Sopel 9.0 will drop support for it.',
         file=sys.stderr,
     )
 
@@ -54,8 +55,6 @@ def read_reqs(path):
 
 
 requires = read_reqs('requirements.txt')
-if sys.version_info[0] < 3:
-    requires.append('backports.ssl_match_hostname')
 dev_requires = requires + read_reqs('dev-requirements.txt')
 
 setup(