Add requires.io badge

README.md

@@ -2,6 +2,7 @@
 
 [![Build Status](https://travis-ci.org/flaskbb/flaskbb.svg?branch=master)](https://travis-ci.org/flaskbb/flaskbb)
 [![codecov](https://codecov.io/gh/flaskbb/flaskbb/branch/master/graph/badge.svg)](https://codecov.io/gh/flaskbb/flaskbb)
+[![requires](https://requires.io/github/flaskbb/flaskbb/requirements.svg?branch=master)](https://requires.io/github/flaskbb/flaskbb/requirements/?branch=master)
 [![License](https://img.shields.io/badge/license-BSD-blue.svg)](https://flaskbb.org)
 [![flaskbb@freenode](https://img.shields.io/badge/irc.freenode.net-%23flaskbb-blue.svg)](https://webchat.freenode.net/?channels=flaskbb)