Remove support for python 3.6

Author: paul121

.github/workflows/run-tests.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [ 3.6, 3.7, 3.8, 3.9 ]
+        python-version: [ 3.7, 3.8, 3.9 ]
     steps:
       - name: Checkout the repository
         uses: actions/checkout@v2

setup.py

@@ -26,7 +26,7 @@
         "License :: OSI Approved :: GNU General Public License v3 (GPLv3)",
         "Operating System :: OS Independent",
     ],
-    python_requires=">=3.6",
+    python_requires=">=3.7",
     setup_requires=setup_requires,
     install_requires=install_requires,
     tests_require=tests_require,