* prepare to execute test suite in different rails version (using Appraisal gem)
* include bootstrap applications in rails 3.x, 4.0 and 4.1
* add Contributing section to README explaining how to run test suite in all rails versions
fail tests when RailsConfig default constant (Settings) is not available in config/application.rb or config/environments/*.rb
fixed compatibility with Rails 4.1 (fixes #72)
Bump to 0.4.1