Merge pull request #634 from dr-uji/master

Update README.md

Author: ujibang

README.md

@@ -7,6 +7,7 @@
 [![javadoc](https://javadoc.io/badge2/org.restheart/restheart-commons/javadoc.svg)](https://javadoc.io/doc/org.restheart/restheart-commons)
 [![Docker Pulls](https://img.shields.io/docker/pulls/softinstigate/restheart.svg?maxAge=2592000)](https://hub.docker.com/r/softinstigate/restheart/)
 [![Join the chat on Slack](https://img.shields.io/badge/chat-on%20slack-orange)](https://join.slack.com/t/restheart/shared_invite/zt-1olrhtoq8-5DdYLBWYDonFGEALhmgSXQ)
+[![CLA assistant](https://cla-assistant.io/readme/badge/SoftInstigate/restheart)](https://cla-assistant.io/SoftInstigate/restheart) 
 
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