Fix failed spec to click header's heading in Kata

Author: yasulab

spec/features/header_spec.rb

@@ -16,7 +16,7 @@
     end
     scenario "Kataに飛ぶ" do
       all(:link_or_button, 'Kata').first.click
-      expect(page).to have_selector 'h1', text:'CoderDojo Kata'
+      expect(page).to have_selector 'h1', text:'📚 Kata'
     end
   end
 end