Fix test workflow to meet 1.2 testing strategy

.github/workflows/pythonapp.yml

@@ -9,10 +9,10 @@ jobs:
       uses: actions/setup-python@v1
       with:
         python-version: 3.x
-    - name: Install dependencies
+    - name: Install flake8
       run: |
-        python -m pip install --upgrade pip
-        pip install -r requirements.txt -r requirements-dev.txt
+        python -m pip install --upgrade setuptools pip
+        pip install flake8
     - name: Lint with flake8
       run: |
         # stop the build if there are Python syntax errors or undefined names