.circleci/config.yml

config.yml

version: 2
jobs:
  build:
    docker:
      - image: circleci/ruby:2.5.3-node-browsers
    working_directory: ~/repos
    steps:
      - checkout
      - run:
          name: install bundler
          command: gem install bundler -v '<2'
      - run:
          name: install dependencies
          command: bundle install
      - run:
          name: run RuboCop
          command: bundle exec rubocop
      - run:
          name: update repository
          command: bundle exec rake repos:update
      - run:
          name: check repository
          command: bundle exec rake repos:check

Rakefile

dir = File.expand_path(__dir__)

namespace :cert do
  desc 'update cert'
  task :update do
    require 'httparty'
    File.write(
      File.join(dir, 'cert/cacert.pem'),
      HTTParty.get('https://curl.haxx.se/ca/cacert.pem'),
    )
  end

  desc 'check cert'
  task :check do
    if `git status`.include?('cacert.pem')
      STDERR.puts 'cert is not fresh.'
      exit 1
    end
  end
end

namespace :bundle do
  desc 'update gems'
  task :update do
    sh 'bundle update'
  end

  desc 'check gems'
  task :check do
    if `git status`.include?('Gemfile.lock')
      STDERR.puts 'gems is not fresh.'
      exit 1
    end
  end
end

namespace :repos do
  desc 'update cert/gems'
  task update: ['cert:update', 'bundle:update']

  desc 'check cert/gems'
  task check: ['cert:check', 'bundle:check']
end