AO3-6765 Use double quotes in skin preview message

Author: nicolacleary

config/locales/controllers/en.yml

@@ -319,7 +319,7 @@ en:
       remove_skin: Go back or follow any link to remove the skin.
       return_to_skin: Return to Skin to Use
       skin_title: You are previewing the skin %{title}.
-      tip: 'Tip: You can preview any archive page you want by adding ''?site_skin=%{site_skin_id}'' to the end of the URL.'
+      tip: 'Tip: You can preview any archive page you want by adding "?site_skin=%{site_skin_id}" to the end of the URL.'
     set:
       failure: Sorry, but only certain skins can be used this way (for performance reasons). Please drop a support request if you'd like %{skin_title} to be added!
       skin_page: "%{skin_title} skin page"

features/other_b/skin_public.feature

@@ -113,8 +113,8 @@ Feature: Public skins
   Then I should be on OTW_Translation's works page
     And I should see "You are previewing the skin Usable Skin."
     And I should see "Go back or follow any link to remove the skin"
-    And I should see "Tip: You can preview any archive page you want by adding '?site_skin="
-    And I should see "' to the end of the URL"
+    And I should see 'Tip: You can preview any archive page you want by adding "?site_skin='
+    And I should see '" to the end of the URL'
   When I follow "Return to Skin to Use"
   Then I should be on "Usable Skin" skin page