AppVeyor: add status badge README.md

README.md

@@ -1,4 +1,5 @@
-[![Build Status](https://travis-ci.org/vcmi/vcmi.svg?branch=develop)](https://travis-ci.org/vcmi/vcmi)
+[![Travis Build Status](https://travis-ci.org/vcmi/vcmi.svg?branch=develop)](https://travis-ci.org/vcmi/vcmi)
+[![AppVeyor Build status](https://ci.appveyor.com/api/projects/status/github/vcmi/vcmi?branch=develop&svg=true)](https://ci.appveyor.com/project/vcmi/vcmi)
 [![Coverity Scan Build Status](https://scan.coverity.com/projects/vcmi/badge.svg)](https://scan.coverity.com/projects/vcmi)
 # VCMI Project
 VCMI is work-in-progress attempt to recreate engine for Heroes III, giving it new and extended possibilities. To use VCMI you need to own original data files.