Mark Swift 2.3 compatibility

Author: radex

README.md

@@ -4,7 +4,7 @@
 [![CI Status](https://api.travis-ci.org/radex/SwiftyTimer.svg?branch=master)](https://travis-ci.org/radex/SwiftyTimer)
 [![CocoaPods](http://img.shields.io/cocoapods/v/SwiftyTimer.svg)](https://cocoapods.org/pods/SwiftyTimer)
 [![Carthage compatible](https://img.shields.io/badge/Carthage-compatible-4BC51D.svg?style=flat)](#carthage)
-![Swift version](https://img.shields.io/badge/swift-2.2-orange.svg)
+![Swift version](https://img.shields.io/badge/swift-2.2,%202.3-orange.svg)
 
 #### Modern Swifty API for `NSTimer`
 ###### SwiftyTimer allows you to instantly schedule delays and repeating timers using convenient closure syntax. It's time to get rid of Objective-C cruft.