Add update_attribute method to Mongoid Shim for devise tests, to fix failing test

Mongoid does not have this method in the current beta version (2.0.0.beta.20).

test/integration/http_authenticatable_test.rb

@@ -56,7 +56,7 @@ class HttpAuthenticationTest < ActionController::IntegrationTest
     assert_match "<email>user@test.com</email>", response.body
     assert warden.authenticated?(:user)
   end
-  
+
   private
 
     def sign_in_as_new_user_with_http(username="user@test.com", password="123456")
@@ -64,11 +64,11 @@ class HttpAuthenticationTest < ActionController::IntegrationTest
       get users_path(:format => :xml), {}, "HTTP_AUTHORIZATION" => "Basic #{ActiveSupport::Base64.encode64("#{username}:#{password}")}"
       user
     end
-    
+
     # Sign in with oauth2 token. This is just to test that it isn't misinterpreted as basic authentication
     def add_oauth2_header
       user = create_user
       get users_path(:format => :xml), {}, "HTTP_AUTHORIZATION" => "OAuth #{ActiveSupport::Base64.encode64("#{user.email}:123456")}"
     end
 
-end
+end

test/rails_app/app/mongoid/shim.rb

@@ -17,8 +17,13 @@ module Shim
     end
   end
 
-  # overwrite equality (because some devise tests use this for asserting model equality) 
+  # overwrite equality (because some devise tests use this for asserting model equality)
   def ==(other)
     other.is_a?(self.class) && _id == other._id
   end
+
+  # Mongoid does not have this method in the current beta version (2.0.0.beta.20)
+  def update_attribute(attribute, value)
+    update_attributes(attribute => value)
+  end
 end