Fix rails 5 depreciation warning

[lilfaf]

Hi,

This is a just a simple fix to avoid warnings caused by env being depreciated in rails 5.1. We now have to access it through the request object.

Best regards

[DonSchado]

thanks, apparently it was already done: #71

but we need to support the older versions as well. can you take care of this?
(for some reason the travis build status is not visible here?)

[lilfaf]

oh my bad ! I didn't noticed PR #71. I'll try to fix the specs and ensure backward compatibility when I get some free time. 😉

[DonSchado]

thx again for raising this, we will finally take care of this in #82