also build python 3.9 eggs

Author: RonnyPfannschmidt

.github/workflows/python-tests.yml

@@ -75,13 +75,21 @@ jobs:
     name: Python ${{ matrix.python_version }} eggs
     strategy:
       matrix:
-        python_version: ['2.7', '3.5', '3.6', '3.7', '3.8']
+        python_version: ['2.7', '3.5', '3.6', '3.7', '3.8', '3.9-dev']
     steps:
     - uses: actions/checkout@v1
-    - name: Set up Python
-      uses: actions/setup-python@v1
+    - name: Setup python
+      uses: actions/setup-python@v2
+      if: matrix.python_version != '3.9-dev'
       with:
         python-version: ${{ matrix.python_version }}
+        architecture: x64
+    - name: Set up Python ${{ matrix.python_version }} (deadsnakes)
+      uses: deadsnakes/[email protected]
+      if: matrix.python_version == '3.9-dev'
+      with:
+        python-version: ${{ matrix.python_version }}
+        architecture: x64
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip