CodeCov setup for parallel_test gem

Rakefile

namespace :codecov do
  desc 'Uploads the latest simplecov result set to codecov.io'
  task upload: :environment do
    require 'simplecov'
    require 'codecov'

    formatter = SimpleCov::Formatter::Codecov.new
    formatter.format(SimpleCov::ResultMerger.merged_result)
  end
end

script.build.sh

# After the specs have finished

if [ $SPECS_RESULT == 0 ]; then
  rake codecov:upload
fi

spec_helper.rb

require 'simplecov'
SimpleCov.start

# You no longer need to require codecov or add the SimpleCov::Formatter::Codecov formatter
# require 'codecov'
# SimpleCov.formatter = SimpleCov::Formatter::Codecov