Update README.md

Author: sjkelly

README.md

@@ -2,7 +2,7 @@
 
 [![Build Status](https://travis-ci.org/JuliaIO/SerialPorts.jl.svg?branch=master)](https://travis-ci.org/JuliaIO/SerialPorts.jl)
 
-[![SerialPorts](http://pkg.julialang.org/badges/SerialPorts_0.7.svg)](http://pkg.julialang.org/?pkg=SerialPorts)
+[![Build status](https://ci.appveyor.com/api/projects/status/8ugea0ou2ray29xk/branch/master?svg=true)](https://ci.appveyor.com/project/sjkelly/serialports-jl/branch/master)
 
 SerialPorts.jl lets you work with devices over serial communication with Julia.
 It is designed to mimic regular file IO as in the Base Julia library.
@@ -34,4 +34,4 @@ The `Arduino` submodule provides functionality for manipulating Arduinos over
 serial. `SerialPorts.Arduino.reset(s::SerialPort)` will reset an Arduino.
 
 ## License
-Available under the [MIT License](https://en.wikipedia.org/wiki/MIT_License). See: [LICENSE.md](./LICENSE.md).
+Available under the [MIT License](https://en.wikipedia.org/wiki/MIT_License). See: [LICENSE.md](./LICENSE.md).