Split test suite into multiple simultaneous builds

First add this extra gem to your Gemfile:

gem "peak_flow_utils"

Change your `peak_flow.yml` to something like the following:

before_script:
  - RAILS_ENV=test bundle exec rake db:schema:load
builds:
  build_1:
    name: RSpec 1
    script:
      - bundle exec rspec `bundle exec peak_flow_rspec_files --groups=3 --group-number=1`
  build_2:
    name: RSpec 2
    script:
      - bundle exec rspec `bundle exec peak_flow_rspec_files --groups=3 --group-number=2`
  build_3:
    name: RSpec 3
    script:
      - bundle exec rspec `bundle exec peak_flow_rspec_files --groups=3 --group-number=3`
  build_5
    name: Rubocop
    script:
      - bundle exec rubocop

Now edit the project on PeakFlow and set the number if simultaneous builds to 5.

5 builds should now start every time you push. And 4 of those builds are going to run your testsuite in parallel.