add unit tests to GH workflow

Author: douglowe

.github/workflows/unit_tests.yml

@@ -0,0 +1,28 @@
+name: Unit Tests
+
+on:
+  pull_request:
+    branches: [ develop ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install -r requirements.txt
+          pip install pytest
+
+      - name: Run tests (excluding integration tests)
+        run: |
+          pytest --ignore=tests/test_integration.py