do not build with Python 3.6

Author: jschlyter

.github/workflows/test.yml

@@ -23,7 +23,6 @@ jobs:
     strategy:
       matrix:
         python-version:
-          - "3.6"
           - "3.7"
           - "3.8"
           - "3.9"

README.md

@@ -1,7 +1,7 @@
 # cryptojwt
 
 ![License](https://img.shields.io/badge/license-Apache%202-blue.svg)
-![Python version](https://img.shields.io/badge/python-3.6%20%7C%203.7%7C%203.8%20%7C%203.9%20%7C%203.10-blue.svg)
+![Python version](https://img.shields.io/badge/python-3.7%7C%203.8%20%7C%203.9%20%7C%203.10%20%7C%203.11-blue.svg)
 [![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/psf/black)
 
 An implementation of the JSON cryptographic specs JWS, JWE, JWK, and JWA [RFC 7515-7518] and JSON Web Token (JWT) [RFC 7519]