Add pytest run to CI install workflow

Install pytest in the install workflow and add a step to run pytest against the tests/ directory with verbose output. Ensures unit tests are executed as part of the CI install job.

Author: kozo2

.github/workflows/install.yml

@@ -18,3 +18,7 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           pip install -e '.[all]'
+          pip install pytest
+      - name: Run tests
+        run: |
+          pytest tests/ -v