Update index.html

removed downloads:
            <section id="downloads">
              <a class="zip_download_link" href="https://github.com/CatanDice/CatanDice-iPhoneApp/zipball/master">Download this project as a .zip file</a>
              <a class="tar_download_link" href="https://github.com/CatanDice/CatanDice-iPhoneApp/tarball/master">Download this project as a tar.gz file</a>
            </section>