Removing IdentityMap as it is no longer part of Mongoid

lib/mongoid/versioning/monkey_patches.rb

@@ -313,7 +313,6 @@ def instantiate(attrs = nil, criteria_instance_id = nil)
         doc.criteria_instance_id = criteria_instance_id
         doc.instance_variable_set(:@attributes, attributes)
         doc.apply_defaults
-        IdentityMap.set(doc) unless _loading_revision?
         yield(doc) if block_given?
         doc.run_callbacks(:find) unless doc._find_callbacks.empty?
         doc.run_callbacks(:initialize) unless doc._initialize_callbacks.empty?

spec/mongoid/versioning_spec.rb

@@ -497,37 +497,4 @@ class WikiPage
     end
   end
 
-  context "when the identity map is enabled" do
-
-    before do
-      Mongoid.identity_map_enabled = true
-    end
-
-    after do
-      Mongoid.identity_map_enabled = false
-    end
-
-    context "when updating a loaded attribute" do
-
-      let!(:page) do
-        WikiPage.create(title: "first")
-      end
-
-      let!(:loaded) do
-        WikiPage.find(page.id)
-      end
-
-      before do
-        loaded.update_attribute(:title, "revised")
-      end
-
-      let(:reloaded) do
-        WikiPage.find(page.id)
-      end
-
-      it "returns the revised im memory document" do
-        reloaded.title.should eq("revised")
-      end
-    end
-  end
 end

spec/spec_helper.rb

@@ -59,7 +59,6 @@ class Application < Rails::Application
   # Drop all collections and clear the identity map before each spec.
   config.before(:each) do
     Mongoid.purge!
-    Mongoid::IdentityMap.clear
   end
 
   # On travis we are creating many different databases on each test run. We