Multi branch deploy gitlab side

gitlab-ci.yml

image: "ruby:2.3.3"

before_script:
  - ruby -v
  - which ruby
  - gem install bundler --no-ri --no-rdoc
  - bundle install --jobs $(nproc) "${FLAGS[@]}"

staging_deploy:
  except:
    - master
    - stable
  script:
    - mkdir -p ~/.ssh
    - touch ~/.ssh/known_hosts
    - ssh-keyscan -H "$STAGING_SERVER_IP" >> ~/.ssh/known_hosts

    - 'which ssh-agent || ( apt-get update -y && apt-get install openssh-client -y )'

    - eval $(ssh-agent -s)
    - ssh-add <(echo "$DEPLOYER_PRIVATE_KEY")

    - bundle exec cap production deploy BRANCH=$CI_COMMIT_REF_NAME VIA_ADMIN=1