Issue openmessaging#7 Refactor design picture

Author: zhouxinyu

README.md

@@ -1,12 +1,12 @@
-## ![logo](./assets/images/logo2.png)
+## ![logo](assets/images/logo-color.png)
 
 [![Build Status](https://travis-ci.org/openmessaging/openmessaging-java.svg?branch=master)](https://travis-ci.org/openmessaging/openmessaging-java) [![Maven Central](https://maven-badges.herokuapp.com/maven-central/io.openmessaging/openmessaging-api/badge.svg)](http://search.maven.org/#search%7Cga%7C1%7Copenmessaging) [![Gitter chat](https://badges.gitter.im/gitterHQ/gitter.png)](https://gitter.im/openmessaging/public) [![License](https://img.shields.io/badge/license-Apache%202-4EB1BA.svg)](https://www.apache.org/licenses/LICENSE-2.0.html)
 
 ### A vendor-neutral open standard for distributed messaging and streaming
 OpenMessaging, which includes the establishment of industry guidelines and messaging, streaming specifications to provide a common framework for finance, e-commerce, IoT and big-data area. The design principles are the cloud-oriented, simplicity, flexibility, and language independent in distributed heterogeneous environments. Conformance to these specifications will make it possible to develop a heterogeneous messaging applications across all major platforms and operating systems.
 
 ## The domain architecture
-![domain-design](./assets/images/new-domain-design.png)
+![domain-design](assets/images/domain-design.png)
 
 ## Doc
 [API Doc](https://openmessaging.github.io/openmessaging-cloud/).