docs(readme): Add semantic-release badge 😎

Author: lpatino10

README.md

@@ -5,6 +5,7 @@
 [![Slack](https://wdc-slack-inviter.mybluemix.net/badge.svg)](https://wdc-slack-inviter.mybluemix.net)
 [![npm-version](https://img.shields.io/npm/v/watson-developer-cloud.svg)](https://www.npmjs.com/package/watson-developer-cloud)
 [![npm-downloads](https://img.shields.io/npm/dm/watson-developer-cloud.svg)](https://www.npmjs.com/package/watson-developer-cloud)
+[![semantic-release](https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg)](https://github.com/semantic-release/semantic-release)
 
 Node.js client library to use the Watson APIs.