Fix Swift version naming

Author: Hans Seiffert

.swift-version

@@ -1 +1 @@
-3
+3.0

README.md

@@ -5,7 +5,7 @@
 [![Carthage compatible](https://img.shields.io/badge/Carthage-compatible-4BC51D.svg?style=flat)](https://github.com/tschob/AudioPlayerManager)
 [![License](https://img.shields.io/cocoapods/l/AudioPlayerManager.svg?style=flat)](http://cocoadocs.org/docsets/AudioPlayerManager)
 [![Platform](https://img.shields.io/cocoapods/p/AudioPlayerManager.svg?style=flat)](http://cocoadocs.org/docsets/AudioPlayerManager)
-[![Language: Swift 3](https://img.shields.io/badge/Swift-3-orange.svg)](https://swift.org)
+[![Language: Swift 3.0](https://img.shields.io/badge/Swift-3.0-orange.svg)](https://swift.org)
 
 ## Feature