function font_awesome() {
if (!is_admin()) {
wp_register_style('font-awesome', 'https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.6.3/css/font-awesome.min.css');
wp_enqueue_style('font-awesome');
}
}
add_action('wp_enqueue_scripts', 'font_awesome'); 
<?php
if ( ! defined( 'ABSPATH' ) ) {
exit; // Exit if accessed directly
}
?><!DOCTYPE html>
<html <?php language_attributes(); ?>>
<head>
<meta charset="<?php bloginfo( 'charset' ); ?>">
<!--[if IE]>
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<![endif]-->
<meta name="viewport" content="user-scalable=no, width=device-width, initial-scale=1.0" />
<meta name="apple-mobile-web-app-capable" content="yes" />
<link rel="profile" href="http://gmpg.org/xfn/11">
<link rel="pingback" href="<?php bloginfo( 'pingback_url' ); ?>">
<script src="https://use.fontawesome.com/0bf9f09e94.js"></script>
<?php wp_head(); ?>
</head>
<body <?php body_class(); ?>>
<?php do_action('draven/action/before_render_body'); ?>
<div id="page" class="site">
<div class="site-inner"><?php
Draven()->layout()->render_header_tpl();
Draven()->layout()->render_page_title_bar_layout_tpl();
.icon-plus:before { content: '\e812'; }