Fastfile.rb

  desc 'Renew push certifications and store them on the server'
  lane :renew_certificate do
    fastlane_require 'spaceship'
    config = whitelabel(type: :store, download: false)

    # If we are at the limit of push certificates (2), then revoke
    # the oldest.
    Spaceship::Portal.login
    existing_certificates = Spaceship::Portal.certificate.production_push.all
                              .select {|c| c.owner_name == config.bundle_id }
                              .sort_by(&:expires)

    if existing_certificates.count == 2
      UI.message "Found 2 existing push certificates; revoking the oldest"
      existing_certificates.first.revoke!
    end

    pem(force: true, new_profile: Proc.new { |pem| upload_pem(config, pem) })
  end