Test padrino-helpers 0.12.0
Fixes #452
Merge pull request #511 from zzak/padrino_test

Test padrino-helpers 0.12.0
Update README.rdoc

clarify that paginate_array does not work on the array inline, but instead returns a new PaginatableArray.
Use instance variable in paginate_array example from #515

https://github.com/amatsuda/kaminari/pull/515#issuecomment-35795767
Test activerecord ~> 4.0.0 in active_record_40 gemfile

This changes from using '>=' which would install the latest version of
activerecord available at the time of running `bundle install`.
Support testing activerecord 4.1 from git.

This could be changed once Rails 4.1 is released to use rubygems, but it
might also be interesting to test against the stable branch for
regressions.
Remove tilt dependency since it's already required upstream
Test kaminari against Ruby 2.1.1