updated python in ci

.github/workflows/ci.yml

@@ -9,14 +9,14 @@ jobs:
     strategy:
       max-parallel: 4
       matrix:
-        python-version: [3.8]
+        python-version: [3.9]
 
     steps:
     - uses: actions/checkout@v1
-    - name: Set up Python 3.8
+    - name: Set up Python 3.9
       uses: actions/setup-python@v1
       with:
-        python-version: 3.8
+        python-version: 3.9
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip