My CSS file includes but not my JavaScript file, what's wrong?

<?php
/* ASSIGN GLOBAL VARIABLES
 *--------------------------------------------------------------------------
*/

$plugin_url     = WP_PLUGIN_URL . '/wpgithub-statistics';
$options        = array();

 /*
  * SETTINGS PAGE
  * Add a link to the plugin admin menu under 'Settings > GitHub Statistics'
  *-------------------------------------------------------------------------
  *
 */

function wpgithub_statistics_menu(){

    /* Use the add_options_page_function
     * add_options_page( $page_title, $menu_title, $capability, $menu-slug, $function )
     *
    */

    add_options_page(
        'GitHub Statistics Plugin',
        'GitHub Statistics',
        'manage_options',
        'wpgithub-statistics',
        'wpgithub_statistics_options_page'
    );
}
add_action( 'admin_menu', 'wpgithub_statistics_menu' );

//Logga in här
//if-sats runt kommande funktioner
//styrfunktion kolla status på sidladdning
//isLogged == true ladda kommande

function wpgithub_statistics_options_page(){

    global $plugin_url;
    global $options;

    if( !current_user_can( 'manage_options' ) ) {

        wp_die( 'You do not have sufficient permission to access this page.' );
    }


    if( isset( $_POST['wpgithub_statistics_form_submitted'] ) ){

        $hidden_field = esc_html($_POST['wpgithub_statistics_form_submitted']);

        if( $hidden_field == 'Y' ){

            $wpgithub_statistics_username   = esc_html( $_POST['wpgithub_statistics_username'] );
            $wpgithub_statistics_profile    = wpgithub_statistics_get_user_profile( $wpgithub_statistics_username );
            $wpgithub_statistics_user_repos = wpgithub_statistics_get_user_repos( $wpgithub_statistics_username );
            $wpgithub_statistics_user_orgs  = wpgithub_statistics_get_user_orgs( $wpgithub_statistics_username );
            //$wpgithub_statistics_org_name   = wpgithub_statistics_get_org_name();
            //$wpgithub_statistics_org_repos  = wpgithub_statistics_get_org_repos( $wpgithub_statistics_org_name );

            $options[ 'wpgithub_statistics_username' ]   = $wpgithub_statistics_username;
            $options[ 'wpgithub_statistics_profile' ]    = $wpgithub_statistics_profile;
            $options[ 'wpgithub_statistics_user_repos' ] = $wpgithub_statistics_user_repos;
            $options[ 'wpgithub_statistics_user_orgs' ]  = $wpgithub_statistics_user_orgs;
            //$options[ 'wpgithub_statistics_org_name' ]   = $wpgithub_statistics_org_name;
            //$options[ 'wpgithub_statistics_org_repos' ]  = $wpgithub_statistics_org_repos;
            $options[ 'last_updated' ]                   = time();

            update_option( 'wpgithub_statistics', $options );
        }
    }

    $options = get_option( 'wpgithub_statistics' );

    if ( $options != '' ) {

        $wpgithub_statistics_username   = $options[ 'wpgithub_statistics_username' ];
        $wpgithub_statistics_profile    = $options[ 'wpgithub_statistics_profile' ];
        $wpgithub_statistics_user_repos = $options[ 'wpgithub_statistics_user_repos' ];
        $wpgithub_statistics_user_orgs  = $options[ 'wpgithub_statistics_user_orgs' ];
        //$wpgithub_statistics_org_name   = $options[ 'wpgithub_statistics_org_name' ];
        //$wpgithub_statistics_org_repos  = $options[ 'wpgithub_statistics_org_repos' ];
    }
    require(  'inc/options-page-wrapper.php' );
}

function wpgithub_statistics_get_user_profile( $wpgithub_statistics_username ){

    $json_feed_url = 'https://api.github.com/users/' . $wpgithub_statistics_username;
    $args = array( 'timeout' => 120 );
    $json_feed = wp_remote_get( $json_feed_url, $args );
    $wpgithub_statistics_profile = json_decode( $json_feed['body'] );

    return $wpgithub_statistics_profile;
}

function wpgithub_statistics_refresh_user_profile(){

    $options = get_option( 'wpgithub_statistics' );
    $last_updated = $options[ 'last_updated' ];
    $current_time = time();
    $update_difference = $current_time - $last_updated;

    if ( $update_difference > 86400 ){

        $wpgithub_statistics_username = $options[ 'wpgithub_statistics_username' ];

        $options['wpgithub_statistics_user_profile'] = wpgithub_statistics_get_user_profile( $wpgithub_statistics_username );
        $options['last_updated'] = time();

        update_option( 'wpgithub_statistics', $options );
    }

    die(); //for the ajax to know when the function is completed

}
add_action( 'wp_ajax_wpgithub_statistics_refresh_user_profile', 'wpgithub_statistics_refresh_user_profile' );

function wpgithub_statistics_get_user_repos( $wpgithub_statistics_username ){
    $json_feed_url = 'https://api.github.com/users/' . $wpgithub_statistics_username . '/repos';
    $args = array( 'timeout' => 120 );
    $json_feed = wp_remote_get( $json_feed_url, $args );
    $wpgithub_statistics_user_repos = json_decode( $json_feed['body'] );

    return $wpgithub_statistics_user_repos;
}

function wpgithub_statistics_get_user_orgs( $wpgithub_statistics_username ){

    $json_feed_url = 'https://api.github.com/users/' . $wpgithub_statistics_username . '/orgs';
    $args = array( 'timeout' => 120 );
    $json_feed = wp_remote_get( $json_feed_url, $args );
    $wpgithub_statistics_user_orgs = json_decode( $json_feed['body'] );

    return $wpgithub_statistics_user_orgs;
}

function wpgithub_statistics_backend_styles(){
    wp_enqueue_style( 'wpgithub_statistics_backend_styles_css', plugins_url( 'wpgithub-statistics/style/wpgithub-statistics.css' ) ); 

}
add_action( 'admin_head', 'wpgithub_statistics_backend_styles' );

function wpgithub_statistics_frontend_scripts_and_styles(){
    wp_enqueue_style( 'wpgithub_statistics_frontend_css', plugins_url( 'wpgithub-statistics/style/wpgithub-statistics.css' ) );
    //array declare dependency of jquery, ignore version nr, true for display in footer instead of hesder
    wp_enqueue_script( 'wpgithub_statistics_frontend_js', plugins_url( 'wpgithub-statistics/script/wpgithub-statistics.js' ), array('jquery'), '', true ); 

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

function wpgithub_statistics_enable_frontend_ajax(){
    //instruction to wordpress that when an ajax command is submitted - pass it through admin and down to the function
?>
    <script>
        var ajaxurl = '<?php echo admin_url('admin-ajax.php'); ?>';
    </script>
<?php


}
add_action( 'wp_head', 'wpgithub_statistics_enable_frontend_ajax' );
?>