http://devcenter.bitrise.io/tips-and-tricks/use-bitrise-yml-from-repository

bitrise.yml

format_version: 4
default_step_lib_source: https://github.com/bitrise-io/bitrise-steplib.git
#project_type: macos

trigger_map:
- push_branch: '*'
  workflow: test
- pull_request_target_branch: '*'
  workflow: test

workflows:
  _repo:
    steps:
    - activate-ssh-key: {}
    - git-clone: {}
    - script:
        #title: continue from repo
        inputs:
        - content: bitrise run $BITRISE_TRIGGERED_WORKFLOW_ID
  test:
    after_run:
    - _repo