Template Override

<?php

add_filter('template_include', 'book_template_override_filter');
function book_template_override_filter($template) {
    if ( 'book' == get_post_type() ) {
        if ( $theme_file = locate_template(array('single-book.php')) ) {
            $file = $theme_file;
        } else {
            $file = plugin_dir_path(__FILE__) . 'views/single-book.php';
        }
        $template = $file;
    }
    return $template;
}

?>