Fix link to Travis CI in README

Author: terop

README.md

@@ -1,6 +1,6 @@
 # Ring
 
-[![Build Status](https://travis-ci.org/ring-clojure/ring.svg?branch=master)](https://travis-ci.org/ring-clojure/ring)
+[![Build Status](https://app.travis-ci.com/ring-clojure/ring.svg?branch=master)](https://app.travis-ci.com/github/ring-clojure/ring)
 
 Ring is a Clojure web applications library inspired by Python's WSGI
 and Ruby's Rack. By abstracting the details of HTTP into a simple,