Add travis shield to README

README.md

@@ -1,4 +1,4 @@
-# FLEX
+# FLEX [![Build Status](https://travis-ci.org/Flipboard/FLEX.svg?branch=master)](https://travis-ci.org/Flipboard/FLEX)
 FLEX (Flipboard Explorer) is a set of in-app debugging and exploration tools for iOS development. When presented, FLEX shows a toolbar that lives in a window above your application. From this toolbar, you can view and modify nearly every piece of state in your running application.
 
 ![View Hierarchy Exploration](http://engineering.flipboard.com/assets/flex/basic-view-exploration.gif)