Update ci.yml

.github/workflows/ci.yml

@@ -23,16 +23,16 @@ jobs:
           - os: ubuntu-20.04
             python-version: "3.6"
     steps:
-    - uses: actions/checkout@v3
-    - name: Set up Python 3.10
-      uses: actions/setup-python@v3
+    - uses: actions/checkout@v2
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v2
       with:
-        python-version: "3.10"
+        python-version: ${{ matrix.python-version }}
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install flake8 pytest
-        if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+        python -m pip install flake8 pytest
+        python -m pip install . -U
     - name: Lint with flake8
       run: |
         # stop the build if there are Python syntax errors or undefined names