feat(workflow): run python tests

.github/workflows/backend-test.yml

@@ -0,0 +1,36 @@
+name: Python package
+
+on: [push]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      max-parallel: 4
+      matrix:
+        python-version: [3.8]
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v1
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+    - name: Lint with flake8
+      working-directory: backend
+      run: |
+        pip install flake8
+        flake8 --show-source app.py
+    - name: Lint with black
+      working-directory: backend
+      run: |
+        pip install black
+        black --check app.py
+    - name: Lint with isort
+      working-directory: backend
+      run: |
+        pip install isort
+        isort --check-only app.py