Add CocoaPods badge to README

Author: jonreid

README.md

@@ -1,5 +1,7 @@
 ![XcodeCoverage](http://qualitycoding.org/jrwp/wp-content/uploads/2016/01/XcodeCoverage@2x.png)
 
+[![CocoaPods Version](https://cocoapod-badges.herokuapp.com/v/XcodeCoverage/badge.png)](http://cocoapods.org/pods/XcodeCoverage)
+
 XcodeCoverage provides a simple way to generate reports of the code coverage of your Xcode project. Generated reports include HTML and Cobertura XML.
 
 Coverage data excludes Apple's SDKs, and the exclusion rules can be customized.