dubbo-parent是头文件不包含依赖。替换成dubbo, 同时增加zk连接的依赖。因为curator-framework在dubbo-dependencies当中去除掉了zookeeper的包，所以外部使用的时候需要额外配置. (#3516)

Author: awayings

README.md

@@ -60,13 +60,25 @@ There's a [README](https://github.com/apache/incubator-dubbo-samples/tree/master
 <dependencies>
     <dependency>
         <groupId>org.apache.dubbo</groupId>
-        <artifactId>dubbo-parent</artifactId>
+        <artifactId>dubbo</artifactId>
         <version>${dubbo.version}</version>
     </dependency>
     <dependency>
         <groupId>io.netty</groupId>
         <artifactId>netty-all</artifactId>
     </dependency>
+    <dependency>
+        <groupId>org.apache.curator</groupId>
+        <artifactId>curator-framework</artifactId>
+    </dependency>
+    <dependency>
+        <groupId>org.apache.curator</groupId>
+        <artifactId>curator-recipes</artifactId>
+    </dependency>
+    <dependency>
+        <groupId>org.apache.zookeeper</groupId>
+        <artifactId>zookeeper</artifactId>
+    </dependency>
 </dependencies>
 ```