Adds truthiness (presence) check with `?`

This allows checking the presence of `Settings.foo` with
`Settings.foo?`.
Merge pull request #26 from brianstanwyck/master

Adds truthiness (presence) check with `?`
Merge pull request #25 from iamvery/rails4

WIP: Rails 4 compatibility
Adds Jay and Brian to contributors
Version bump
Fix rails 4 deprecation