add travis build label

Author: Zdravko

README.md

@@ -1,4 +1,4 @@
-# Background Upload NativeScript plugin
+# Background Upload NativeScript plugin [![Build Status](https://travis-ci.org/NativeScript/nativescript-background-http.svg?branch=master)](https://travis-ci.org/NativeScript/nativescript-background-http)
 
 A cross platform plugin for [the NativeScript framework](http://www.nativescript.org), that provides background upload for iOS and Android.
 
@@ -83,4 +83,4 @@ Please, use [github issues](https://github.com/NativeScript/nativescript-backgro
 ## License
 
 Apache License Version 2.0, January 2004
-![](https://ga-beacon.appspot.com/UA-111455-24/nativescript/nativescript-background-http?pixel)
+![](https://ga-beacon.appspot.com/UA-111455-24/nativescript/nativescript-background-http?pixel)