Update build status badge

Author: daniellevass

README.md

@@ -1,6 +1,6 @@
 # Pusher Channels Swift Client (also works with Objective-C)
 
-[![Build Status](https://travis-ci.org/pusher/pusher-websocket-swift.svg?branch=master)](https://travis-ci.org/pusher/pusher-websocket-swift)
+![Build Status](https://app.bitrise.io/app/3c6dac112b98e7fe.svg?token=n0z-aWua_Bc35kUGu4qpYg)
 ![Languages](https://img.shields.io/badge/languages-swift%20%7C%20objc-orange.svg)
 [![Platform](https://img.shields.io/cocoapods/p/PusherSwift.svg?style=flat)](http://cocoadocs.org/docsets/PusherSwift)
 [![Cocoapods Compatible](https://img.shields.io/cocoapods/v/PusherSwift.svg)](https://img.shields.io/cocoapods/v/PusherSwift.svg)