Update user wall (#2436)

README.md

@@ -90,7 +90,7 @@ Follow this [document](docs/en/guides/How-to-build.md).
 A wide variety of companies and organizations use SkyWalking for research, production and commercial product.
 Here is the **User Wall** of SkyWalking.
 
-<img src="http://skywalking.apache.org/assets/users-20190222.png"/>
+<img src="http://skywalking.apache.org/assets/users-20190402.png"/>
 
 Users are encouraged to add themselves to the [PoweredBy](docs/powered-by.md) page.
 

docs/powered-by.md

@@ -60,6 +60,7 @@ or providing commercial products including Apache SkyWalking.
 1. Source++ https://sourceplusplus.com
 1. StartDT 奇点云 https://www.startdt.com/
 1. Successchannel 苏州渠成易销网络科技有限公司. http://www.successchannel.com
+1. Tetrate.io https://www.tetrate.io/
 1. Today36524.com Today便利店
 1. Tools information technology co. LTD 杭州图尔兹信息技术有限公司 http://bintools.cn/
 1. Tsfinance.com 重庆宜迅联供应链科技有限公司 https://www.tsfinance.com.cn/
@@ -90,11 +91,15 @@ Deploy SkyWalking in production enviroments.
 
 Support 60+ Instances, Over 300k Calls Per Minute, Over 50k Spans Per Second
 
+## Oscart
+Use multiple language agents from SkyWalking and its ecosystem, including SkyWalking Javaagent and [SkyAPM nodejs agent](https://github.com/SkyAPM/SkyAPM-nodejs). SkyWalking OAP platform acts as backend and visualization.
+
 ## Primeton
 Integrated in Primeton EOS PLATFORM 8, which is a commercial micro-service platform.
 
-## Oscart
-Use multiple language agents from SkyWalking and its ecosystem, including SkyWalking Javaagent and [SkyAPM nodejs agent](https://github.com/SkyAPM/SkyAPM-nodejs). SkyWalking OAP platform acts as backend and visualization.
+## Tetrate
+Tetrate provides enterprise level service mesh. SkyWalking acts as the core observability platform for hybrid
+enterprise service mesh environment.
 
 ## Qiniu Cloud
 Provide a customized version SkyWalking agent. It could provide distributed tracing and integrated in its intelligence log management platform.