Cat/Snapshots 'repository' param is not in-fact required, despite spec

Author: polyfractal

src/Elasticsearch/Endpoints/Cat/Snapshots.php

@@ -39,14 +39,12 @@ public function setRepository($repository)
      */
     public function getURI()
     {
-        if (isset($this->repository) !== true) {
-            throw new RuntimeException(
-                'repository is required for Cat Snapshots '
-            );
-        }
         $repository = $this->repository;
-        $uri   = "/_cat/snapshots/$repository/";
-        return $uri;
+        if (isset($this->repository) === true) {
+            return "/_cat/snapshots/$repository/";
+        }
+
+        return "/_cat/snapshots/";
     }
 
     /**