Add a test for custom error reporting

i.e. using different values for error_reporting and the Bugsnag
`setErrorReportingLevel` option

tests/phpt/handler_should_respect_error_suppression_operator_with_custom_reporting_level.phpt

@@ -0,0 +1,34 @@
+--TEST--
+Bugsnag\Handler should respect the error suppression operator with a custom reporting level
+--FILE--
+<?php
+$client = require __DIR__ . '/_prelude.php';
+$client->getConfig()->setErrorReportingLevel(E_ALL & ~E_USER_NOTICE);
+error_reporting(E_ALL & ~E_USER_WARNING);
+
+Bugsnag\Handler::register($client);
+
+echo "Triggering a user notice that should be reported by PHP and ignored by Bugsnag\n";
+trigger_error('abc notice', E_USER_NOTICE);
+
+echo "Triggering a suppressed user notice that should be ignored by PHP and ignored by Bugsnag\n";
+@trigger_error('xyz notice', E_USER_NOTICE);
+
+echo "Triggering a user warning that should be ignored by PHP and reported by Bugsnag\n";
+trigger_error('abc warning', E_USER_WARNING);
+
+echo "Triggering a suppressed user warning that should be ignored by PHP and ignored by Bugsnag\n";
+@trigger_error('xyz warning', E_USER_WARNING);
+?>
+--EXPECTF--
+Triggering a user notice that should be reported by PHP and ignored by Bugsnag
+
+Notice: abc notice in %s on line 9
+Triggering a suppressed user notice that should be ignored by PHP and ignored by Bugsnag
+Triggering a user warning that should be ignored by PHP and reported by Bugsnag
+Triggering a suppressed user warning that should be ignored by PHP and ignored by Bugsnag
+Guzzle request made (1 event)!
+* Method: 'POST'
+* URI: 'http://localhost/notify'
+* Events:
+    - abc warning