Merge pull request #286 from Renumics/feature/enable-ci-on-pr

Also run CI workflow on `pull_request` event

.github/workflows/ci.yml

@@ -1,6 +1,8 @@
 name: CI
 
-on: push
+on:
+    - push
+    - pull_request
 
 # As long as we use local actions, checkout should be made in workflow before
 # and not in the local actions. Otherwise, no action file found.