Javascript External CSS Injector

inject.js

var Inject = {
  externalCSS: function(href) {
    var css = document.createElement('link');
    css.href = href;
    css.type = 'text/css';
    css.rel = 'stylesheet';
    var head = document.getElementsByTagName('head')[0];
    head.appendChild(css);
  },
  fontAwesome: function(){
    this.externalCSS("https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.3.0/css/font-awesome.min.css");
  }
}
Inject.fontAwesome();