Add Branch to README.md (spark-jobserver#955)

Author: raravena80

README.md

@@ -90,6 +90,7 @@ Spark Job Server is now included in Datastax Enterprise 4.8!
 - [Datadog](https://www.datadoghq.com/)
 - [Planalytics](http://www.planalytics.com)
 - [Target](http://www.target.com/)
+- [Branch](http://branch.io)
 
 ## Features