Fix errors#blank? when save is stubbed to false

Sync with empty?

Author: lulalala

lib/rspec/active_model/mocks/mocks.rb

@@ -147,6 +147,7 @@ def self.param_delimiter; "-"; end
           [:save, :update_attributes, :update].each do |key|
             if stubs[key] == false
               RSpec::Mocks.allow_message(m.errors, :empty?).and_return(false)
+              RSpec::Mocks.allow_message(m.errors, :blank?).and_return(false)
             end
           end
         end

spec/rspec/active_model/mocks/mock_model_spec.rb

@@ -81,20 +81,23 @@
       it "is empty" do
         model = mock_model(MockableModel)
         expect(model.errors).to be_empty
+        expect(model.errors).to be_blank
       end
     end
 
     context "with :save => false" do
       it "is not empty" do
         model = mock_model(MockableModel, :save => false)
         expect(model.errors).not_to be_empty
+        expect(model.errors).not_to be_blank
       end
     end
 
     context "with :update_attributes => false" do
       it "is not empty" do
         model = mock_model(MockableModel, :save => false)
         expect(model.errors).not_to be_empty
+        expect(model.errors).not_to be_blank
       end
     end
   end