Remove travis link from README

Author: ogoffart

README.md

@@ -2,7 +2,6 @@
 
 The qmetaobject crate is a crate which is used to expose rust object to Qt and QML.
 
-[![Travis Build Status](https://travis-ci.org/woboq/qmetaobject-rs.svg?branch=master)](https://travis-ci.org/woboq/qmetaobject-rs)
 [![Appveyor Build status](https://ci.appveyor.com/api/projects/status/8l5te3wlj2ie4njc/branch/master?svg=true)](https://ci.appveyor.com/project/ogoffart/qmetaobject-rs/branch/master)
 [![Crates.io](https://img.shields.io/crates/v/qmetaobject.svg)](https://crates.io/crates/qmetaobject)
 [![Documentation](https://docs.rs/qmetaobject/badge.svg)](https://docs.rs/qmetaobject/)