Merge pull request #335 from thephpleague/tests-on-pr

updating gha to run test on pr

Author: ragboyjr

.github/workflows/php.yml

@@ -1,6 +1,12 @@
 name: PHP
 
-on: [push]
+on:
+  pull_request:
+    branches:
+      - v3
+  push:
+    branches:
+      - v3
 
 jobs:
   run: