Remove Python 3.10 testing because it doesn't appear to be available in GitHub Actions yet

Author: tleonhardt

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        python-version: [3.6, 3.7, 3.8, 3.9, 3.10]
+        python-version: [3.6, 3.7, 3.8, 3.9]
       fail-fast: false
     runs-on: ${{ matrix.os }}
     steps:

noxfile.py

@@ -15,7 +15,7 @@ def docs(session):
                 '-d', '{}/doctrees'.format(tmpdir), '.', '{}/html'.format(tmpdir))
 
 
-@nox.session(python=['3.6', '3.7', '3.8', '3.9', '3.10'])
+@nox.session(python=['3.6', '3.7', '3.8', '3.9'])
 @nox.parametrize('plugin', [None,
                             'ext_test',
                             'template',