phpunit 5.1 compat

tests/TestSpeedTrap.php

@@ -106,6 +106,8 @@ END;
 
   public function addRiskyTest(PHPUnit_Framework_Test $test, Exception $e, $time) {}
 
+  public function addWarning(PHPUnit_Framework_Test $test, PHPUnit_Framework_Warning $e, $time) {}
+
 
   protected function collect($name, $speed) {
     $count = count(self::$_speed_trapped_test);