RSpec: Good simplecov config using Guard notifier

spec_helper_with_simplecov.rb

require 'simplecov'
SimpleCov.start do 
  add_filter '/db/'    
  add_filter '/config/'
  add_filter '/spec/'
  add_filter '/public/'
  add_filter '/lib/' # Feel free to write coverage for the StudentScrape

  SimpleCov.at_exit do
    SimpleCov.result.format!

    result = SimpleCov.result
    percentage = result.covered_lines / Float(result.total_lines) * 100
    text = result.covered_lines.to_s
    text << " / " + result.total_lines.to_s
    text << " lines - " + percentage.to_s + "%"

    Guard::Notifier.notify(
      text,
      :title => "SimpleCov",
      :image => percentage < 95 ? :failed : :success
    )
  end
end