Add test workflow

.github/workflows/unit-tests.yml

@@ -0,0 +1,20 @@
+name: Run Unit Tests
+
+on:
+  pull_request:
+
+jobs:
+  spm-test:
+    runs-on: macos-latest
+    steps:
+      - name: Checkout Code
+        uses: actions/checkout@v4
+
+      - name: Set up Swift
+        uses: swift-actions/setup-swift@v2
+
+      - name: Build
+        run: swift build
+
+      - name: Run Unit Tests
+        run: swift test