Fix fix for failing failed test -.-

tests/PHPUnit/BaseFixture.php

@@ -178,7 +178,7 @@ abstract class Test_Piwik_BaseFixture extends PHPUnit_Framework_Assert
      */
     public static function checkBulkTrackingResponse($response) {
         self::assertJson($response);
-        $data = json_decode($response);
+        $data = json_decode($response, true);
         self::assertArrayHasKey('status', $data);
         self::assertEquals('success', $data['status']);
     }