Add: [Actions] flake8, black, and docker build tests (#2)

Currently this doesn't do anything of course, but this allows for
later Pull Request to be validated before merge.

.flake8

@@ -0,0 +1,8 @@
+[flake8]
+max-line-length = 120
+inline-quotes = double
+
+# We use 'black' for coding style; these next two warnings are not PEP-8
+# compliant.
+# E231 is a bug in 'black', see https://github.com/psf/black/issues/1202
+ignore = E203, E231, W503

.github/workflows/testing.yml

@@ -0,0 +1,44 @@
+name: Testing
+
+on:
+  push:
+    branches:
+    - master
+  pull_request:
+
+jobs:
+  docker:
+    name: Docker build
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+    - name: Build
+      run: docker build .
+
+  flake8:
+    name: Flake8
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+    - name: Flake8
+      uses: TrueBrain/actions-flake8@master
+      with:
+        path: content_api
+
+  black:
+    name: Black
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+    - name: Set up Python 3.8
+      uses: actions/setup-python@v1
+      with:
+        python-version: 3.8
+    - name: Black
+      run: |
+        python -m pip install --upgrade pip
+        pip install black
+        black -l 120 --check content_api

Dockerfile

@@ -0,0 +1,2 @@
+FROM python:3.8-slim
+