Improve specs

spec/helpers/icons_helper_spec.rb

@@ -4,12 +4,14 @@ describe IconsHelper do
   describe 'icon' do
     it 'returns aria-hidden by default' do
       star = icon('star')
+
       expect(star['aria-hidden']).to eq 'aria-hidden'
     end
 
     it 'does not return aria-hidden if aria-label is set' do
       up = icon('up', 'aria-label' => 'up')
-      expect(up['aria-hidden']).to eq nil
+
+      expect(up['aria-hidden']).to be_nil
       expect(up['aria-label']).to eq 'aria-label'
     end
   end