Update Travis CI URL

Author: atouchet

README.md

@@ -1,7 +1,7 @@
 rust-url
 ========
 
-[![Travis build Status](https://travis-ci.org/servo/rust-url.svg?branch=master)](https://travis-ci.org/servo/rust-url) [![Appveyor build status](https://ci.appveyor.com/api/projects/status/ulkqx2xcemyod6xa?svg=true)](https://ci.appveyor.com/project/Manishearth/rust-url)
+[![Travis build Status](https://travis-ci.com/servo/rust-url.svg?branch=master)](https://travis-ci.com/servo/rust-url) [![Appveyor build status](https://ci.appveyor.com/api/projects/status/ulkqx2xcemyod6xa?svg=true)](https://ci.appveyor.com/project/Manishearth/rust-url)
 
 URL library for Rust, based on the [URL Standard](https://url.spec.whatwg.org/).