Kubernetes cache support

The documentation explicitly says that if you want to use cache do these steps and I did but it didn't cache the specified directory .gitlab-ci.yml includes this

  cache:
    paths:
    - /root/.cache

and the results I think there should be an option for specifying a volume to cache but there isn't

Possible Workarounds

• using host/mount paths: #1906 (comment 75349325)
• using minio: #1906 (comment 65897542)