Use strings for python versions

3.10 was interpreted as 3.1

Author: mvantellingen

.github/workflows/python-test.yml

@@ -29,7 +29,7 @@ jobs:
     strategy:
       max-parallel: 4
       matrix:
-        python-version: [3.6, 3.7, 3.8,3.9,3.10]
+        python-version: ["3.6", "3.7", "3.8", "3.9", "3.10"]
     steps:
     - uses: actions/checkout@v2
     - name: Set up Python ${{ matrix.python-version }}