Changed all gems to use greater than (>=) rather than requiring minor version (~>)
Removing include of Mongoid::Timestamps. Should not be forced by this gem.
updated/created_accessor now return nil if updated/created_column is nil. (Previously was throwing can't find nil key error)
Merge branch 'removed-timestamps' into safe-nil
Merge remote-tracking branch 'remotes/origin/gems-greater-than' into safe-nil
Added rspec tests
Merge pull request #6 from johnnyshields/master

Safe handling of nils + RSpec tests + removed Mongoid::Timestamps + updated Gem dependency versions