IN-1729 - Add sniffer to validate this code against it's own rules in CI pipeline

Author: vladimir-flyeralarm

.github/workflows/php.yml

@@ -38,5 +38,8 @@ jobs:
     - name: phpcs version
       run: vendor/bin/phpcs --version
 
+    - name: Validate code style
+      run: vendor/bin/phpcs -w -p -s --standard=ruleset.xml --ignore="tests/*not-allowed*" custom-standards/ tests/
+
     - name: Run test suite
       run: php tests/runner.php