Restored Travic CI build status button

Author: verklov

README.md

@@ -1,3 +1,5 @@
+[![Build Status](https://travis-ci.org/magento/magento2.svg?branch=master)](https://travis-ci.org/magento/magento2)
+
 Welcome to Magento 2 installation! We're glad you chose to install Magento 2, a cutting edge, feature-rich eCommerce solution that gets results.
 
 #### Contents 
@@ -795,4 +797,4 @@ Note the lack of a slash character between <tt>magento2</tt> and <tt>index.php</
 
 Magento 2 static assets should be located under `[your Magento install dir]/pub/static/` (there should be `frontend` and `adminhtml` directories).
 
-Verify your server rewrites setting and your base URL and try again.
+Verify your server rewrites setting and your base URL and try again.