updates CI budge

Author: Oleh Dokuka

README.md

@@ -15,7 +15,7 @@ Learn more at http://rsocket.io
 
 ## Build and Binaries
 
-[![Build Status](https://travis-ci.org/rsocket/rsocket-java.svg?branch=develop)](https://travis-ci.org/rsocket/rsocket-java)
+[![Build Status](https://github.com/rsocket/rsocket-java/actions/workflows/gradle-main.yml/badge.svg?branch=master)](https://github.com/rsocket/rsocket-java/actions/workflows/gradle-main.yml)
 
 ⚠️ The `master` branch is now dedicated to development of the `1.1.x` line.