tests: add inline comments on the python app.json file

This is the most-used app and therefore most-used app.json file, so this should allow us to test that moving to a new json parser works as expected.

tests/apps/python/app.json

@@ -14,7 +14,9 @@
   },
   "scripts": {
     "dokku": {
+      // this is a comment for the postdeploy script
       "postdeploy": "touch /app/postdeploy.test",
+      // this is a comment for the predeploy script
       "predeploy": "touch /app/predeploy.test"
     }
   }