Add 'request', 'request_cache' to ClearCache endpoint

Author: polyfractal

src/Elasticsearch/Endpoints/Indices/Cache/Clear.php

@@ -48,7 +48,9 @@ public function getParamWhitelist()
             'recycler',
             'ignore_unavailable',
             'allow_no_indices',
-            'expand_wildcards'
+            'expand_wildcards',
+            'request_cache',
+            'request'
         );
     }