Fix appveyor badge

Author: alexcrichton

README.md

@@ -1,7 +1,7 @@
 # socket2-rs
 
 [![Build Status](https://travis-ci.org/alexcrichton/socket2-rs.svg?branch=master)](https://travis-ci.org/alexcrichton/socket2-rs)
-[![Build status](https://ci.appveyor.com/api/projects/status/68vjengx3n0rg843?svg=true)](https://ci.appveyor.com/project/alexcrichton/socket2-rs)
+[![Build status](https://ci.appveyor.com/api/projects/status/hovebj1gr4bgm3d9?svg=true)](https://ci.appveyor.com/project/alexcrichton/socket2-rs)
 
 [Documentation](https://docs.rs/socket2)