Config version is the only thing that requires Rails

[rgalanakis]

Hello! I am using this Gem outside of rails (for the model extensions). I was using 1.22 fine, but 1.23 broke, due to this change: b153aee#diff-aa3c971e8e946ba7c6f1c01666f55614R8

Basically, the only thing that requires Rails is that line, to get the Rails version. Otherwise, this gem has been totally safe to import into non-Rails. Is changing this line and supporting first-class non-Rails usage in line for this Gem, or is the non-Rails usage a coincidence and you've no wish to support it?

(My use case is Grape and Sequel, btw)

Thank you!