🔥 Drop Python 2.7 and 3.6 support

Python 2.7 reached end of life in 2020-01-01 and 3.6 in 2021-12-23, refs:
https://devguide.python.org/versions/

Add support for Python 3.11

Author: AndreMiras

.github/workflows/tests.yml

@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python: ["2.7", "3.6", "3.7", "3.8", "3.9", "3.10", pypy-3.7, pypy-3.8, pypy-3.9]
+        python: ["3.7", "3.8", "3.9", "3.10", "3.11", pypy-3.7, pypy-3.8, pypy-3.9]
 
     steps:
       - uses: actions/checkout@v3
@@ -21,7 +21,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python: ["2.7", "3.6", "3.7", "3.8", "3.9", "3.10", pypy-3.7, pypy-3.8, pypy-3.9]
+        python: ["3.7", "3.8", "3.9", "3.10", "3.11", pypy-3.7, pypy-3.8, pypy-3.9]
 
     steps:
       - uses: actions/checkout@v3

setup.py

@@ -20,13 +20,12 @@
         'Operating System :: OS Independent',
         'Operating System :: POSIX',
         'Programming Language :: C',
-        'Programming Language :: Python :: 2',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
         'Programming Language :: Python :: 3.9',
         'Programming Language :: Python :: 3.10',
+        'Programming Language :: Python :: 3.11',
         'Programming Language :: Python :: Implementation :: CPython',
         'Topic :: Software Development :: Libraries :: Python Modules',
         ],