Use GitHub actions for CI (#7)

.github/workflows/test.yml

@@ -0,0 +1,28 @@
+name: Unit tests
+
+on: [push]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python_version: [3.7]
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up Python 3.7
+      uses: actions/setup-python@v1
+      with:
+        python-version: ${{ matrix.python_version }}
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pipenv
+        pipenv install --dev
+    - name: Test with pytest
+      env:
+        CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
+      run: |
+        pipenv run pytest --cov=./
+        pipenv run codecov