fix

composer.json

@@ -4,6 +4,7 @@
   "keywords": ["search","client", "elasticsearch"],
   "type": "library",
   "license": "Apache-2.0",
+  "minimum-stability": "dev",
   "authors": [
     {
       "name": "Zachary Tong"
@@ -12,7 +13,7 @@
   "require": {
     "php": "^7.0",
     "ext-json": ">=1.3.7",
-    "ringphp_33cn": "@dev",
+    "ringphp_33cn": "2.0",
     "psr/log": "~1.0"
   },
   "require-dev": {