A new block has been released on the Moodle plugins database by Nicolas Connault which adds the tabs on the top of the course. It is a very simple block with no configuration settings.
Simply add it to a course in Topics or Weeks format (and all sections shown on the same page) and it will add tabbed navigation to the course. Each tab links to a section (except section 0 which is always shown just below the tabs).
It is compatible with all Bootstrap themes available in the Moodle themes database. You can also adjust the style of the block by modifying its stylesheet named as styles.css
To download the latest version of the tabbed navigation block, please check out this link: https://moodle.org/plugins/view/block_tabbed_navigation