fix ubuntu/python3.6 version issue, upgrade action version

.github/workflows/tests.yaml

@@ -12,14 +12,17 @@ jobs:
     name: Run unit tests with mock requests
     strategy:
       matrix:
-        os: [macos-latest, ubuntu-latest]
+        os: [ubuntu-latest, macos-latest]
-        python-version: ['3.6', '3.10']
+        python-version: ['3.10']
+        include:
+          - os: ubuntu-20.04
+            python-version: '3.6'
     runs-on: ${{ matrix.os }}
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v3
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install dependencies
@@ -43,14 +46,14 @@ jobs:
     name: Run unit tests online
     strategy:
       matrix:
-        os: [ubuntu-latest]
+        platform: [linux]
         python-version: ['3.10']
-    runs-on: ${{ matrix.os }}
+    runs-on: ${{ matrix.platform }}
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v3
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install dependencies
@@ -78,7 +81,7 @@ jobs:
     if: github.event_name == 'schedule'
 
     steps:
-      - uses: actions/setup-python@v2
+      - uses: actions/setup-python@v3
       - name: install test
         run: |
           pip install -U pip