Add build badge to README

[skip ci]

Author: dbent

README.md

@@ -1,5 +1,7 @@
-# Artwork
+# Artwork [![Build status][build-badge]][build]
 
 Artwork for [Apokee][apokee] projects.
 
 [apokee]: http://www.apokee.com/
+[build]: https://ci.appveyor.com/project/Apokee/artwork/branch/develop
+[build-badge]: https://ci.appveyor.com/api/projects/status/yvwxjrvicl3man59/branch/develop