Adding a link to the hhvm issue that makes a test fail

tests/TestCase/I18n/TimeTest.php

@@ -549,6 +549,7 @@ class TimeTest extends TestCase
     /**
      * test formatting dates with offset style timezone
      *
+     * @see https://github.com/facebook/hhvm/issues/3637
      * @return void
      */
     public function testI18nFormatWithOffsetTimezone()