remove trailing whitespace. [ci skip]

guides/source/caching_with_rails.md

@@ -105,7 +105,7 @@ This method generates a cache key that depends on all products and can be used i
 <% end %>
 ```
 
-If you want to cache a fragment under certain condition you can use `cache_if` or `cache_unless` 
+If you want to cache a fragment under certain condition you can use `cache_if` or `cache_unless`
 
 ```erb
 <% cache_if (condition, cache_key_for_products) do %>

guides/source/upgrading_ruby_on_rails.md

@@ -82,10 +82,10 @@ secrets, you need to:
 
 2. Use your existing `secret_key_base` from the `secret_token.rb` initializer to
    set the SECRET_KEY_BASE environment variable for whichever users run the Rails
-   app in production mode. Alternately, you can simply copy the existing 
-   `secret_key_base` from the `secret_token.rb` initializer to `secrets.yml` 
+   app in production mode. Alternately, you can simply copy the existing
+   `secret_key_base` from the `secret_token.rb` initializer to `secrets.yml`
    under the `production` section, replacing '<%= ENV["SECRET_KEY_BASE"] %>'.
-   
+
 3. Remove the `secret_token.rb` initializer.
 
 4. Use `rake secret` to generate new keys for the `development` and `test` sections.