Set up appraisal and test for rails 3.2.x, 4.0.x and 4.1.0
Fix typo ;)
Fix deprecation warning about terminator string in rails 4.1

Related rails code:

https://github.com/rails/rails/blob/febfc57e56558bd6924b39a38f08d833a78e975b/activesupport/lib/active_support/callbacks.rb#L670-L728
Remove accidentally commited gemfile lock files
Merge remote-tracking branch 'origin/master' into mcls-rails-4.1
Notes on how to run tests against all Rails versions.