only test python when needed

Author: donbing

.github/workflows/lint-and-test-python.yml

@@ -3,7 +3,11 @@
 
 name: Lint and test python
 
-on: [push]
+on:
+  push:
+    paths:
+      - 'src/**'
+      - 'tests/**'
 
 jobs:
   build:
@@ -31,8 +35,3 @@ jobs:
     - name: Test with unittest
       run: |
         python3 -m unittest discover -s tests -v
-    # - name: Commit & Push changes
-    #   uses: actions-js/push@master
-    #   with:
-    #     github_token: ${{ secrets.GITHUB_TOKEN }}
-    #     branch: ${{ github.ref }}