Update README.md - Build status broken link

Author: Eric Baptista

README.md

@@ -1,6 +1,6 @@
 # Logstash Plugin
 
-[![Travis Build Status](https://travis-ci.com/logstash-plugins/logstash-input-tcp.svg)](https://travis-ci.com/logstash-plugins/logstash-input-tcp)
+[![Travis Build Status](https://app.travis-ci.com/logstash-plugins/logstash-input-tcp.svg)](https://app.travis-ci.com/github/logstash-plugins/logstash-input-tcp)
 
 This is a plugin for [Logstash](https://github.com/elastic/logstash).