added a diff to Commit files action for debugging

.github/workflows/python-test.yml

@@ -44,6 +44,7 @@ jobs:
               run: |
                 git config --local user.email "github-actions[bot]@users.noreply.github.com"
                 git config --local user.name "github-actions[bot]"
+                git diff
                 git add coverage.svg
                 git commit -m "update coverage badge"