Locking doesn't work if model has presence validators

[dementrock]

For example I have the following toy model:

class Toy
  include Mongoid::Document
  include Mongoid::OptimisticLocking
  belongs_to :owner, class_name: 'User'
  validates_presence_of :owner
end

Then even the following code would fail (in rails console)

> a = Toy.create owner: User.first
(reload console)
> Toy.first.save
Mongoid::Errors::StaleDocument: Attempted to update a stale document: Toy

[tomdmaguire]

This should be closed by #14

[burgalon]

New version 0.0.4 published to Rubygems. Thank you @tomglue