Merge pull request #3640 from martinbean/patch-1

[5.2] Make Memcached options configurable.

config/cache.php

@@ -51,7 +51,9 @@ return [
             'driver'  => 'memcached',
             'servers' => [
                 [
-                    'host' => '127.0.0.1', 'port' => 11211, 'weight' => 100,
+                    'host' => env('MEMCACHED_HOST', '127.0.0.1'),
+                    'port' => env('MEMCACHED_PORT', 11211),
+                    'weight' => 100,
                 ],
             ],
         ],