Coveralls and CodeClimate formatters for simplecov

spec_helper.rb

# ...

require 'codeclimate-test-reporter'
require 'coveralls'

if ENV['TRAVIS'] == 'true'
  formatters = []

  # don't use `CodeClimate::TestReporter.start` as it will overwrite some .simplecov settings
  if CodeClimate::TestReporter.run?
    formatters << CodeClimate::TestReporter::Formatter
  end

  formatters << Coveralls::SimpleCov::Formatter

  SimpleCov.formatter = SimpleCov::Formatter::MultiFormatter[
    *formatters
  ]
end

# ...