Add first draft of Github CI pipeline.

.github/workflows/testing.yml

@@ -0,0 +1,53 @@
+name: Run tests
+on:
+  push:
+    branches: ["*"]
+    tags-ignore: ["*"]
+  pull_request:
+    branches: ["*"]
+
+jobs:
+
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up python 3.9
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.9
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip setuptools
+          python -m pip install -r requires/lint.txt
+      - name: Flake8
+        run: |
+          flake8 sprockets tests.py
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: [3.7, 3.8, 3.9]
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up python ${{ matrix.python-version }}
+        uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip setuptools
+          python -m pip install -r requires/testing.txt .
+      - name: Run tests
+        run: |
+          coverage run -m unittest tests.py
+          coverage report
+          coverage xml -o ./coverage.xml
+      - name: Send coverage data to codecov.io
+        uses: codecov/codecov-action@v1.3.2
+        if: github.event_name == 'push'
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          file: ./coverage.xml
+          flags: unittests
+          fail_ci_if_error: true