Fixed memcache & unittests

src/Core/Cache/MemcacheCacheDriver.php

@@ -111,6 +111,6 @@ class MemcacheCacheDriver extends AbstractCacheDriver implements IMemoryCacheDri
 	public function add($key, $value, $ttl = Cache::FIVE_MINUTES)
 	{
 		$cachekey = $this->getCacheKey($key);
-		return $this->memcache->add($cachekey, $value, $ttl);
+		return $this->memcache->add($cachekey, serialize($value), MEMCACHE_COMPRESSED, $ttl);
 	}
 }