add_action( 'init', 'lhea_enqueue_custom_scripts' );

function lhea_enqueue_custom_scripts() {
	add_action( 'wp_enqueue_scripts', 'lhea_enqueue_fa_css' , 999 );
}

function lhea_enqueue_fa_css() {
	if ( function_exists('lhea') ) {
		wp_enqueue_style('font-awesome-450', lhea()->plugin_url('assets/css/font-awesome.min.css'), null , '4.5.0' );
	}
}