Adjust tests to work with latest shoulda gem

spec/models/list_spec.rb

@@ -13,12 +13,6 @@ describe List do
     it { is_expected.to validate_presence_of(:position) }
     it { is_expected.to validate_numericality_of(:position).only_integer.is_greater_than_or_equal_to(0) }
 
-    it 'validates uniqueness of label scoped to board_id' do
-      create(:list)
-
-      expect(subject).to validate_uniqueness_of(:label_id).scoped_to(:board_id)
-    end
-
     context 'when list_type is set to closed' do
       subject { described_class.new(list_type: :closed) }
 

spec/models/notification_setting_spec.rb

@@ -13,7 +13,9 @@ RSpec.describe NotificationSetting, type: :model do
     it { is_expected.to validate_presence_of(:level) }
 
     describe 'user_id' do
-      before { subject.user = create(:user) }
+      before do
+        subject.user = create(:user)
+      end
 
       it { is_expected.to validate_uniqueness_of(:user_id).scoped_to([:source_type, :source_id]).with_message(/already exists in source/) }
     end

spec/models/user_spec.rb

@@ -114,7 +114,9 @@ describe User, models: true do
       end
 
       it 'validates uniqueness' do
-        expect(subject).to validate_uniqueness_of(:username).case_insensitive
+        user = build(:user)
+
+        expect(user).to validate_uniqueness_of(:username).case_insensitive
       end
     end