Fix coveralls badge to point to develop

readme.md

-SickRage [![Build Status](https://travis-ci.org/SickRage/SickRage.svg?branch=develop)](https://travis-ci.org/SickRage/SickRage) [![Average time to resolve an issue](http://isitmaintained.com/badge/resolution/SickRage/sickrage-issues.svg)](http://isitmaintained.com/project/SickRage/sickrage-issues "Average time to resolve an issue") [![Percentage of issues still open](http://isitmaintained.com/badge/open/SickRage/sickrage-issues.svg)](http://isitmaintained.com/project/SickRage/sickrage-issues "Percentage of issues still open") [![Coverage Status](https://coveralls.io/repos/SickRage/SickRage/badge.svg?branch=master&service=github)](https://coveralls.io/github/SickRage/SickRage?branch=master)  
+SickRage [![Build Status](https://travis-ci.org/SickRage/SickRage.svg?branch=develop)](https://travis-ci.org/SickRage/SickRage) [![Average time to resolve an issue](http://isitmaintained.com/badge/resolution/SickRage/sickrage-issues.svg)](http://isitmaintained.com/project/SickRage/sickrage-issues "Average time to resolve an issue") [![Percentage of issues still open](http://isitmaintained.com/badge/open/SickRage/sickrage-issues.svg)](http://isitmaintained.com/project/SickRage/sickrage-issues "Percentage of issues still open") [![Coverage Status](https://coveralls.io/repos/SickRage/SickRage/badge.svg?branch=develop&service=github)](https://coveralls.io/github/SickRage/SickRage?branch=develop)  
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 Automatic Video Library Manager for TV Shows. It watches for new episodes of your favorite shows, and when they are posted it does its magic.