add back test

Author: tedchamb

.github/workflows/pythonpackage.yml

@@ -29,3 +29,7 @@ jobs:
         pip install flake8
         # stop the build if there are Python syntax errors or undefined names
         flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
+    - name: Test with pytest
+      run: |
+        pip install pytest
+        pytest