Configuring Diffblue Cover

Added a GitHub Actions workflow `.github/workflows/DiffblueCover.yml` invoking Diffblue Cover on each pull request.
Invoking Diffblue Cover requires a license key, please contact [email protected] to acquire one.
This default workflow configuration should be sufficient for single module Maven projects, but will need further customization for more complex
projects.

## Next steps

- [ ] Ensure that DIFFBLUE_LICENSE_KEY secret is configured in your project.
  - If this wasn't configured when opening the Pull Request then the Job will have failed, but can be re-run once you've configured the above secret.
- [ ] Ensure that the project is built before Diffblue Cover is invoked.
- [ ] Enjoy some AI generated unit tests!

See [Customizing GitHub Actions](https://docs.diffblue.com/customizing-github-actions)
for ideas on further customization.

.github/workflows/DiffblueCover.yml

@@ -0,0 +1,29 @@
+name: Diffblue Cover
+
+on:
+  pull_request:
+
+jobs:
+  Diffblue:
+    runs-on: ubuntu-latest
+    steps:
+
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Setup Java
+        uses: actions/setup-java@v3
+        with:
+          java-version: '8'
+          distribution: 'zulu'
+
+      - name: Maven Install
+        run: mvn --batch-mode install
+
+      - name: Diffblue Cover
+        uses: diffblue/cover-github-action@main
+        with:
+          license-key: ${{ secrets.DIFFBLUE_LICENSE_KEY }}
+
+      - name: Create Tests
+        run: dcover create