adding github actions workflow

.github/workflows/pytests.yaml

@@ -0,0 +1,39 @@
+name: Python Package
+
+on: [push]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.8
+      - name: Install Poetry
+        uses: snok/install-poetry@v1
+        with:
+          virtualenvs-create: true
+          virtualenvs-in-project: true
+      - name: Load cached venv
+        id: cached-poetry-dependencies
+        uses: actions/cache@v2
+        with:
+          path: .venv
+          key: venv-${{ runner.os }}-${{ hashFiles('**/poetry.lock') }}
+      - name: Install dependencies
+        if: steps.cached-poetry-dependencies.outputs.cache-hit != 'true'
+        run: poetry install --no-interaction --no-root
+      - name: Run tests
+        run: |
+          source .venv/bin/activate
+          pytest tests/
+      - name: Run black
+        run: |
+          source .venv/bin/activate
+          black --check --diff .
+      - name: Run flake8
+        run: |
+          source .venv/bin/activate
+          flake8 . --config=.flake8