evansagge/mongoid-rspec — pull request #127 by aomega08 (2014-05-31 10:10:17+00:00)
Title: Support for the new RSpec3 expectation protocol.

RSpec3 keeps yelling that:

Mongoid::Matchers::Validations::ValidateUniquenessOfMatcher implements a legacy RSpec matcher
protocol. For the current protocol you should expose the failure messages
via the `failure_message` and `failure_message_when_negated` methods.

So I added the `failure_message` and `failure_message_when_negated` method aliases to the needed classes.