Drop support for Python 3.6 and 3.7

Sadly GitHub has dropped the ability to run tests with these versions of
Python.

Author: arthurdejong

.github/workflows/test.yml

@@ -9,22 +9,6 @@ on:
     - cron: '9 0 * * 1'
 
 jobs:
-  test_legacy:
-    runs-on: ubuntu-20.04
-    strategy:
-      fail-fast: false
-      matrix:
-        python-version: [3.6, 3.7]
-    steps:
-      - uses: actions/checkout@v3
-      - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v4
-        with:
-          python-version: ${{ matrix.python-version }}
-      - name: Install dependencies
-        run: python -m pip install --upgrade pip tox
-      - name: Run tox
-        run: tox -e "$(echo py${{ matrix.python-version }} | sed -e 's/[.]//g;s/pypypy/pypy/')" --skip-missing-interpreters false
   test:
     runs-on: ubuntu-latest
     strategy:

setup.py

@@ -63,8 +63,6 @@
         'Operating System :: OS Independent',
         'Programming Language :: Python',
         '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',

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py{36,37,38,39,310,311,312,313,py3},flake8,docs,headers
+envlist = py{38,39,310,311,312,313,py3},flake8,docs,headers
 skip_missing_interpreters = true
 
 [testenv]