Fixed ActOnAll test that fails if one driver is unavailable.

Author: Geolim4

tests/ActOnAll.test.php

@@ -27,6 +27,7 @@
     CacheManager::getInstance('Memcached');
 }catch(phpFastCacheDriverCheckException $e){
     try {
+        CacheManager::clearInstances();
         CacheManager::getInstance('Files');
         CacheManager::getInstance('Sqlite');
         CacheManager::getInstance('Memstatic');