Make test to be runnable on Ruby 2.2 x Rails Edge
Make test to be runnable on Ruby 2.2 x Rails Edge

Only Ruby 2.2.2 or newer can run Rails 5.0.

ref: https://github.com/rails/rails/blob/v5.0.0.rc1/guides/source/getting_started.md#guide-assumptions

bonekost/wicked_pdf,mileszs/wicked_pdf