Update specs for MongoidAdditions to use rr mocks

spec/cancan/mongoid_additions_spec.rb

@@ -98,7 +98,7 @@ describe CanCan::MongoidAdditions do
       it "Calls where on the model class when there are criteria" do
         obj = @model_class.create :title  => 'Bird'
         @conditions = {:title.nin => ["Fork", "Spoon"]}      
-        @model_class.should_receive(:where).with(@conditions) {[obj]}
+        mock(@model_class).where(@conditions) {[obj]}
         @ability.can :read, @model_class, @conditions
         @ability.can?(:read, obj)
       end

spec/spec_helper.rb

@@ -5,11 +5,9 @@ require 'supermodel' # shouldn't Bundler do this already?
 require 'active_support/all'
 require 'matchers'
 require 'cancan/matchers'
-require 'mongoid'
-require 'active_support'
 
 RSpec.configure do |config|
-  config.mock_with :rspec
+  config.mock_with :rr
   config.before(:each) do
     Project.delete_all
     Category.delete_all