Remove outdated build info badge

Author: marci4

README.markdown

@@ -1,6 +1,5 @@
 Java WebSockets
 ===============
-[![Build Status](https://travis-ci.org/marci4/Java-WebSocket-Dev.svg?branch=master)](https://travis-ci.org/marci4/Java-WebSocket-Dev)
 [![Javadocs](https://www.javadoc.io/badge/org.java-websocket/Java-WebSocket.svg)](https://www.javadoc.io/doc/org.java-websocket/Java-WebSocket)
 [![Maven Central](https://img.shields.io/maven-central/v/org.java-websocket/Java-WebSocket.svg)](https://mvnrepository.com/artifact/org.java-websocket/Java-WebSocket)