require https before bootstrap + redirect to naked domain

wp-config-pantheon.php

// Redirect all traffic to non-www. For example yoursite.com
if (isset($_SERVER['PANTHEON_ENVIRONMENT']) &&
  ($_SERVER['PANTHEON_ENVIRONMENT'] === 'live') &&
  // Check if Drupal or WordPress is running via command line
  (php_sapi_name() != 'cli')) {
    if ($_SERVER['HTTP_HOST'] == 'www.cast.asu.edu') {
        header('HTTP/1.0 301 Moved Permanently');
        header('Location: http://cast.asu.edu'.$_SERVER['REQUEST_URI']);
        exit();
    }
}

// Require HTTPS.
if (isset($_SERVER['PANTHEON_ENVIRONMENT']) &&
  ($_SERVER['HTTPS'] === 'OFF') &&
  // Check if Drupal or WordPress is running via command line
  (php_sapi_name() != 'cli')) {
    if (!isset($_SERVER['HTTP_X_SSL']) ||
  (isset($_SERVER['HTTP_X_SSL']) && $_SERVER['HTTP_X_SSL'] != 'ON')) {
        header('HTTP/1.0 301 Moved Permanently');
        header('Location: https://'.$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI']);
        exit();
    }
}