Added vendor bug badge to README.md

Author: zbeekman

README.md

@@ -7,6 +7,7 @@ Status
 ------
 [![Build Status](https://img.shields.io/travis/jacobwilliams/json-fortran/master.svg?style=plastic)](https://travis-ci.org/jacobwilliams/json-fortran)
 [![GitHub issues](https://img.shields.io/github/issues/jacobwilliams/json-fortran.png?style=plastic)](https://github.com/jacobwilliams/json-fortran/issues)
+[![Blocked by Vendor Bug](https://badge.waffle.io/jacobwilliams/json-fortran.png?label=vendor%20bug&title=Blocked%20by%20Vendor%20Bug)](https://waffle.io/jacobwilliams/json-fortran)
 [![Ready in backlog](https://badge.waffle.io/jacobwilliams/json-fortran.png?label=Ready&title=Ready)](https://github.com/jacobwilliams/json-fortran/#contributing-)
 [![In Progress](https://badge.waffle.io/jacobwilliams/json-fortran.png?label=In%20Progress&title=In%20Progress)](https://waffle.io/jacobwilliams/json-fortran)
 [![Needs Review](https://badge.waffle.io/jacobwilliams/json-fortran.png?label=Needs%20Review&title=Needs%20Review)](https://waffle.io/jacobwilliams/json-fortran)