To use it with rails 4 we need to upgrade this dependencies.
Looks like this broke compatibility with Ruby 1.8.7 on the Travis CI build. Can you do the same thing with a >= dependency maybe?
fix to work with rails 4
👍 for Rails 4 compatibility.
Is compatibility with Ruby 1.8.7 necessary? That version of Ruby is officially retired now, although some people still might use it.