title: Stop gitlab runner to not remove a directory
body: <p>I have a directory which is generated during a build and it should not be deleted in the next builds. I tried to keep the directory using cache in .gitlab-ci.yml:</p>
  
  <pre><code>cache:
    key: "$CI_BUILD_REF_NAME"
    untracked: true
    paths:
      - target_directory/
  build-runner1:
    stage: build
    script:
      - ./build-platform.sh target_directory
  </code></pre>
  
  <p>In the first build a cache.zip is generated but for the next builds the target_directory is deleted and the cache.zip is extracted which takes a very long time. Here is a log of the the second build:</p>
  
  <pre><code>Running with gitlab-ci-multi-runner 1.11.
    on Runner1
  Using Shell executor...
  Running on Runner1...
  Fetching changes...
  Removing target_directory/
  HEAD is now at xxxxx Update .gitlab-ci.yml
  From xxxx
  Checking out xxx as master...
  Skipping Git submodules setup
  Checking cache for master...
  Successfully extracted cache
  </code></pre>
  
  <p>Is there a way that gitlab runner not remove the directory in the first place?</p>