merge pipeline configuration

merge.json

{
  "name": "$PIPELINE_NAME",
  "description": "Pipeline for $PIPELINE_NAME merge",
  "repository": "$REPOSITORY",
  "default_branch": "master",
  "steps": [
    {
      "type": "script",
      "name": ":buildkite: $PIPELINE_TYPE",
      "command": "buildkite-agent pipeline upload $SERVICE/.buildkite/$PIPELINE_TYPE.yml"
    }
  ],
  "cancel_running_branch_builds": true,
  "skip_queued_branch_builds": true,
  "branch_configuration": "master",
  "provider_settings": {
    "trigger_mode": "code",
    "build_pull_requests": false,
    "publish_blocked_as_pending": true,
    "publish_commit_status_per_step": true
  }
}