fix tests

lib/util/timers.js

@@ -403,6 +403,15 @@ module.exports = {
     onTick()
     onTick()
   },
+  /**
+   * Clear all FastTimers.
+   */
+  clearAll () {
+    fastNow = 0
+    fastTimers.length = 0
+    clearTimeout(fastNowTimeout)
+    fastNowTimeout = null
+  },
   /**
    * Exporting for testing purposes only.
    * Marking as deprecated to discourage any use outside of testing.