Updated Readme.md with swift version badge.

Author: Florian Rieger

README.md

@@ -1,5 +1,6 @@
 # ACInteractor
-[![License](https://img.shields.io/badge/license-Apache%202.0-blue.svg)](https://raw.githubusercontent.com/appcron/acinteractor/master/LICENSE)
+[![License](https://img.shields.io/badge/swift-3.1-orange.svg)](https://swift.org/blog/swift-3-1-released/)
+[![License](https://img.shields.io/badge/license-Apache_2.0-blue.svg)](https://raw.githubusercontent.com/appcron/acinteractor/master/LICENSE)
 
 Swift Package for a Use Case centric architecture as proposed by Robert C. Martin and others.