trigger gh action, didn't run because of no pr event

Author: rbavery

.github/workflows/tests.yml

@@ -1,7 +1,7 @@
 name: Test Python package
 
 on:
-  - push
+  - [push, pull_request]
 
 jobs:
   test:
@@ -50,4 +50,3 @@ jobs:
         run: tox -e format
       - name: Test with tox
         run: tox -e test
-