Add travis badge

Author: d6o

README.md

@@ -1,6 +1,6 @@
 # ![GoTree](https://rawgit.com/DiSiqueira/GoTree/master/gotree-logo.png)
 
-# GoTree ![Language Badge](https://img.shields.io/badge/Language-Go-blue.svg) ![Go Report](https://goreportcard.com/badge/github.com/DiSiqueira/GoTree) ![License Badge](https://img.shields.io/badge/License-MIT-blue.svg) ![Status Badge](https://img.shields.io/badge/Status-Beta-brightgreen.svg) [![GoDoc](https://godoc.org/github.com/DiSiqueira/GoTree?status.svg)](https://godoc.org/github.com/DiSiqueira/GoTree)
+# GoTree ![Language Badge](https://img.shields.io/badge/Language-Go-blue.svg) ![Go Report](https://goreportcard.com/badge/github.com/DiSiqueira/GoTree) ![License Badge](https://img.shields.io/badge/License-MIT-blue.svg) ![Status Badge](https://img.shields.io/badge/Status-Beta-brightgreen.svg) [![GoDoc](https://godoc.org/github.com/DiSiqueira/GoTree?status.svg)](https://godoc.org/github.com/DiSiqueira/GoTree) [![Build Status](https://travis-ci.org/DiSiqueira/GoTree.svg?branch=master)](https://travis-ci.org/DiSiqueira/GoTree)
 
 Simple Go module to print tree structures in terminal. Heavily inpired by [The Tree Command for Linux][treecommand]