title: trying to install ext-gd on heroku
body: <p>i tried adding <code>"ext-gd": "*"</code> to my <code>composer.json</code> file
  (<a href="https://stackoverflow.com/questions/27380365/heroku-how-to-enable-gd-on-heroku-php-application">Heroku - how to enable gd on heroku php application?</a>)</p>
  
  <p>but when i run <code>composer update</code> on the server, i get this response back</p>
  
  <p><code>Your requirements could not be resolved to an installable set of packages.
    Problem 1
      - The requested PHP extension ext-gd * is missing from your system. Install or enable PHP's gd extension.</code></p>
  
  <p>what do i do to install <code>gd extension</code>, im trying to use laravel's socialite library to retrieve the avatar from a user`s profile and this is where it crashes</p>
  
  <p><strong>UPDATE</strong>: </p>
  
  <p>when i use the command <code>composer update --ignore-platform-reqs</code></p>
  
  <p>it doesnt throw an error response, but it doesnt fix the issue, i still get this message thrown back when i try to retrieve the avatar image: </p>
  
  <p><code>GD Library extension not available with this PHP installation.</code></p>
  
  <p>thanks to anyone who helps</p>