[ci skip] Add link to Travis-CI badge

README.md

@@ -3,7 +3,7 @@
 ![iOS 11+](https://img.shields.io/badge/ios-11+-green.svg)
 [![OpenSSL 1.1.0j](https://img.shields.io/badge/openssl-1.1.0j-d69c68.svg)](https://www.openssl.org/news/openssl-1.1.0-notes.html)
 [![License GPLv3](https://img.shields.io/badge/license-GPLv3-lightgray.svg)](LICENSE)
-![Travis-CI](https://api.travis-ci.org/passepartoutvpn/tunnelkit.svg?branch=master)
+[![Travis-CI](https://api.travis-ci.org/passepartoutvpn/tunnelkit.svg?branch=master)](https://travis-ci.org/passepartoutvpn/tunnelkit)
 
 This library provides a simplified Swift/Obj-C implementation of the OpenVPN® protocol for the Apple platforms. The crypto layer is built on top of [OpenSSL][dep-openssl] 1.1.0j, which in turn enables support for a certain range of encryption and digest algorithms.