[SOLVED] Cache not working

I installed drone CI using rancher, everything is working fine, except whenever I place the cache statement in the drone file, its exits with the following error

Failed to unmarshal Stringorslice

pipeline:

  build:
    image: framgia/laravel-workspace
    commands:
      - sleep 180
      - php artisan key:generate
      - composer install
      - php artisan migrate

services:
  database:
    image: mysql
    environment:
      MYSQL_DATABASE: homestead_test
      MYSQL_USER: homestead_test
      MYSQL_PASSWORD: secret
      MYSQL_ROOT_PASSWORD: root
                      
cache:
  mount:
    - .git
    - vendor
    - node_modules

did I do something wrong here ? or is there something wrong with my drone installation ?
I also tried prefixing the mount directories with /drone/ according to the official docs.
what am I missing ?

The cache statement was deprecated in Drone version 0.5, and cache functionality is now handled by third party plugins. Here is a list of cache plugins you can use http://plugins.drone.io/tags/cache/