Ruby 2.2.5 requirement... why?

[davidakachaos]

Transferred from: davidakachaos/workless_revived#15

Thanks for your work on this gem!

I noticed that you dropped support for Ruby < 2.2.5 in the 1.3.0 release. Is there anything major in Ruby 2.2.5 that is necessary for this gem? I'd rather avoid upgrading Ruby versions unneccessarily, I'm currently on 2.2.4.