migrate Travis tests into GitHub actions

.github/workflows/python-tests.yml

@@ -0,0 +1,34 @@
+name: Python Tests
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ['3.7', '3.8', '3.9', '3.10', '3.11', '3.12']
+      fail-fast: false
+
+    steps:
+    - name: Check out code
+      uses: actions/checkout@v3
+
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v3
+      with:
+        python-version: ${{ matrix.python-version }}
+
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install -r requirements.txt
+        python setup.py install
+        pip install coveralls
+
+    - name: Run tests
+      run: coverage run --source=nvd3 setup.py test
+
+    - name: Finish coveralls
+      run: coveralls
+      env: GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}