Sidr Plugin not working for my WordPress Site

I’ve recently tried to install the jQuery Slidr plugin for my custom wordpress theme but haven’t had any luck getting it to work. When I try to call the sidebar to appear by binding it to my ‘#mobile-menu’ anchor tag I get this error in my console, “TypeError: $(…).sidr is not a function”.

Here’s how my code is laid out:

functions.php

function wpbootstrap_scripts_with_jquery()
{

wp_register_script( 'init', get_template_directory_uri() . '/javascripts/initialize.js' , array( 'jquery' ), '1.0', true );
wp_register_script( 'sidr', get_template_directory_uri() . '/javascripts/jquery.sidr.min.js' , array( 'jquery' ), '1.0', true );


wp_enqueue_script( 'init' );
wp_enqueue_script( 'sidr' );

}
add_action( 'wp_enqueue_scripts', 'wpbootstrap_scripts_with_jquery' );

initialize.js

(function($) {
$('#mobile-menu').sidr();
})(jQuery);

Link to my site: http://www.xboxoneachievementguides.com