build: use tox and combine workflows

combine workflows so that tests are executed
before a container is deployed

.github/workflows/docker.yml → .github/workflows/docat.yml

@@ -1,11 +1,44 @@
-name: docker ci
+name: docat ci
 
 on: [push]
 
 jobs:
 
-  build:
+  test:
+    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
+        pip install tox
+
+    - name: lint with flake8
+      working-directory: backend
+      run: |
+        tox -e flake8
+
+    - name: lint with black
+      working-directory: backend
+      run: |
+        tox -e black
+
+    - name: lint with isort
+      working-directory: backend
+      run: |
+        tox -e isort
 
+  docker:
     runs-on: ubuntu-latest
 
     steps:

backend/tox.ini

@@ -1,12 +1,14 @@
 [tox]
-envlist = lint
-skip_missing_interpreters = True
 skipsdist = True
 
-[testenv:lint]
+[testenv:flake8]
 deps = flake8
-       black
-       isort
-commands = flake8 --show-source app.py
-           black --check app.py
-           isort --check-only app.py
+commands = flake8 --show-source app.py {posargs}
+
+[testenv:black]
+deps = black
+commands = black --check app.py {posargs}
+
+[testenv:isort]
+deps = isort
+commands = isort --check-only app.py {posargs}