GitLab deploy only with tags beginning with V

deploy to stage:
  image: ruby:2.2
  stage: deploy
  environment:
    name: foo-bar
  script:
    - apt-get update -yq
    - apt-get install -y ruby-dev
    - gem install dpl
#    - ...
  only:
    #- tags
    - /^V.*$/
      except:
        - branches
        - triggers