Added support for translations
New enqueue script and support for translation in datepicker
Added support for translation in color picker and indented code
Added support for translation in 'save_button'
Removed file date picker
Idented code
Added if for validation CMB_META_BOX_URL

The idea is to be able to customize and have freedom in changing its
path

/**
* Initialize the metabox class.
*/
function cmb_initialize_cmb_meta_boxes() {
    define( 'CMB_META_BOX_URL', trailingslashit(
get_stylesheet_directory_uri() . '/lib/Custom-Metaboxes-and-Fields-for-
WordPress' ) );

    if ( ! class_exists( 'cmb_Meta_Box' ) ) {
        require_once 'lib/Custom-Metaboxes-and-Fields-for-
WordPress/init.php';
    }
}
add_action( 'init', 'cmb_initialize_cmb_meta_boxes', 9999 );
Updated path background
Create field type hidden
Added files with translations
Updated JS with support for translation
Updated translation
Updated support for translation