docs: update badge

Signed-off-by: Bo-Yi Wu <[email protected]>

Author: appleboy

README.md

@@ -2,14 +2,15 @@
 
 [![Run Tests](https://github.com/appleboy/queue/actions/workflows/go.yml/badge.svg?branch=master)](https://github.com/appleboy/queue/actions/workflows/go.yml)
 [![codecov](https://codecov.io/gh/appleboy/queue/branch/master/graph/badge.svg?token=V8A1WA0P5E)](https://codecov.io/gh/appleboy/queue)
+[![Build Status](https://cloud.drone.io/api/badges/appleboy/queue/status.svg)](https://cloud.drone.io/appleboy/queue)
 
 Queue is a Golang library for spawning and managing a Goroutine pool, Alloowing you to create multiple worker according to limit CPU number of machine.
 
 ## Features
 
 * [x] Support [buffered channel](https://gobyexample.com/channel-buffering) queue.
 * [x] Support [NSQ](https://nsq.io/) (A realtime distributed messaging platform) as backend.
-* [ ] Support [NATS](https://nats.io/) (Connective Technology for Adaptive Edge & Distributed Systems) as backend.
+* [x] Support [NATS](https://nats.io/) (Connective Technology for Adaptive Edge & Distributed Systems) as backend.
 
 ## Installation