Add windows build status

README.md

@@ -1,6 +1,7 @@
 # PWMAN3 
 
 [![Build Status](https://travis-ci.org/pwman3/pwman3.png?branch=master)](https://travis-ci.org/pwman3/pwman3)
+[![Build status](https://ci.appveyor.com/api/projects/status/9yxwlj5d15bitshr?svg=true)](https://ci.appveyor.com/project/oz123/pwman3)
 [![Coverage Status](https://coveralls.io/repos/pwman3/pwman3/badge.png)](https://coveralls.io/r/pwman3/pwman3?branch=master)
 [![Documentation Status](https://readthedocs.org/projects/pwman3/badge/?version=latest)](https://readthedocs.org/projects/pwman3/?badge=latest)