Fix `send_key` to `send_keys` and add EOF newline

spec/features/dashboard/shortcuts_spec.rb

@@ -8,11 +8,11 @@ feature 'Dashboard shortcuts', :feature, :js do
     end
 
     scenario 'Navigate to tabs' do
-      find('body').send_key([:shift, 'I'])
+      find('body').send_keys([:shift, 'I'])
 
       check_page_title('Issues')
 
-      find('body').send_key([:shift, 'M'])
+      find('body').send_keys([:shift, 'M'])
 
       check_page_title('Merge Requests')
 
@@ -52,4 +52,4 @@ feature 'Dashboard shortcuts', :feature, :js do
   def check_page_title(title)
     expect(find('.header-content .title')).to have_content(title)
   end
-end
+end
\ No newline at end of file