Fix versions in GitHub Actions

.github/workflows/release.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v2
         with:
-          python-version: 3.8
+          python-version: 3.9
 
       - name: Get pip cache dir
         id: pip-cache

.github/workflows/test.yml

@@ -8,7 +8,7 @@ jobs:
     strategy:
       max-parallel: 5
       matrix:
-        python-version: [2.7, 3.5, 3.6, 3.7, 3.8, 'pypy2', 'pypy3']
+        python-version: [3.6, 3.7, 3.8, 3.9, 3.10, 'pypy3']
 
     steps:
     - uses: actions/checkout@v2