title: Bitbucket Pipeline - PHP extension zip is missing
body: <p>I'm trying to set up pipelines on bitbucket and I'm receiving an error when composer runs</p>
  
  <pre><code>Your requirements could not be resolved to an installable set of packages.
    Problem 1
      - Installation request for craftcms/cms 3.1.24 -&gt; satisfiable by craftcms/cms[3.1.24].
      - craftcms/cms 3.1.24 requires ext-zip * -&gt; the requested PHP extension zip is missing from your system.
  </code></pre>
  
  <p>I'm not sure exactly what I need to add to my <code>bitbucket-pipelines.yml</code> file. </p>
  
  <p>This is my current file:</p>
  
  <pre><code>image: php:7.2
  pipelines:
    branches:
      master:
        - step:
            script:
              - apt-get update &amp;&amp; apt-get install -y unzip git rsync zip 
              - curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer
              - composer install
              - php deploy.php
  </code></pre>
  
  <p>This guy seems to have a similar issue, but I'm not sure how he solved. It's vague and he also seems to have more output regarding mcrypt: <a href="https://stackoverflow.com/questions/48348386/docker-bitbucket-pipelines-ext-zip">Docker: bitbucket pipelines ext-zip *</a></p>
  
  <p>If you're curious, I got my configuration from this suggested commit at fortrabbit.com: <a href="https://gist.github.com/ukautz/4f3219c3eb5d97fbd018027dca4b8808" rel="nofollow noreferrer">https://gist.github.com/ukautz/4f3219c3eb5d97fbd018027dca4b8808</a></p>
  
  <p>The php file it's running is on the link above, but it doesn't reach that yet, so it's irrelevant to my problem</p>
  
  <p>I'm not entirely sure what I have to install or if I'm just not seeing the actual problem logged (for instance if there's more granular logs somewhere and I'm not seeing the actual issue)</p>