Add GHA unit test

.github/workflows/unit-test.yaml

@@ -0,0 +1,36 @@
+on:
+  pull_request:
+  push:
+  workflow_dispatch:
+
+jobs:
+  unit-test:
+    runs-on: ubuntu-18.04
+    container: ubuntu:18.04
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
+        with:
+          python-version: 3.6
+      - name: Install and setup venv
+        run: |
+          apt-get update --yes && apt-get install --yes python3-venv
+          python3 -m venv /srv/venv
+          echo '/srv/venv/bin' >> $GITHUB_PATH
+      - name: Cache pip deps
+        uses: actions/cache@v2
+        with:
+          path: /srv/venv/
+          key: ${{ runner.os }}-pip-dependencies-${{ hashFiles('*setup.py', '*dev-requirements.txt') }}
+      - name: Install Python dependencies
+        run: |
+          python3 -m pip install -U pip==20.0.*
+          python3 -m pip install -r dev-requirements.txt
+          python3 -m pip install -e .
+          pip freeze
+      - name: Run unit tests
+        run: |
+          pytest --cov=tljh tests/
+      - name: Upload code coverage stats
+        run: |
+          codecov