Remove trailing spaces [ci skip]

guides/source/5_0_release_notes.md

@@ -55,7 +55,7 @@ information.
 ### API Applications
 
 Rails can now be used to create slimmed down API only applications.
-This is useful for creating and serving APIs similar to [Twitter](https://dev.twitter.com) or [GitHub](https://developer.github.com) API, 
+This is useful for creating and serving APIs similar to [Twitter](https://dev.twitter.com) or [GitHub](https://developer.github.com) API,
 that can be used to serve public facing, as well as, for custom applications.
 
 You can generate a new api Rails app using:
@@ -77,7 +77,7 @@ This will do three main things:
   you generate a new resource.
 
 The application provides a base for APIs,
-that can then be [configured to pull in functionality](api_app.html) as suitable for the application's needs.  
+that can then be [configured to pull in functionality](api_app.html) as suitable for the application's needs.
 
 See the [Using Rails for API-only Applications](api_app.html) guide for more
 information.

guides/source/action_mailer_basics.md

@@ -413,7 +413,7 @@ inside of Action Controller, so you can use all the same options, such as
 
 #### Caching mailer view
 
-You can perform fragment caching in mailer views like in application views using the `cache` method. 
+You can perform fragment caching in mailer views like in application views using the `cache` method.
 
 ```
 <% cache do %>

guides/source/active_record_querying.md

@@ -1393,7 +1393,7 @@ end
 ```
 
 NOTE: The `default_scope` is also applied while creating/building a record
-when the scope arguments are given as a `Hash`. It is not applied while 
+when the scope arguments are given as a `Hash`. It is not applied while
 updating a record. E.g.:
 
 ```ruby

guides/source/active_support_core_extensions.md

@@ -135,9 +135,9 @@ NOTE: Defined in `active_support/core_ext/object/blank.rb`.
 
 ### `duplicable?`
 
-In Ruby 2.4 most objects can be duplicated via `dup` or `clone` except 
+In Ruby 2.4 most objects can be duplicated via `dup` or `clone` except
 methods and certain numbers. Though Ruby 2.2 and 2.3 can't duplicate `nil`,
-`false`, `true`, and  symbols as well as instances `Float`, `Fixnum`, 
+`false`, `true`, and  symbols as well as instances `Float`, `Fixnum`,
 and `Bignum` instances.
 
 ```ruby

guides/source/caching_with_rails.md

@@ -387,9 +387,9 @@ store is not appropriate for large application deployments. However, it can
 work well for small, low traffic sites with only a couple of server processes,
 as well as development and test environments.
 
-New Rails projects are configured to use this implementation in development environment by default. 
+New Rails projects are configured to use this implementation in development environment by default.
 
-NOTE: Since processes will not share cache data when using `:memory_store`, 
+NOTE: Since processes will not share cache data when using `:memory_store`,
 it will not be possible to manually read, write or expire the cache via the Rails console.
 
 ### ActiveSupport::Cache::FileStore
@@ -580,7 +580,7 @@ Caching in Development
 ----------------------
 
 It's common to want to test the caching strategy of your application
-in development mode. Rails provides the rake task `dev:cache` to 
+in development mode. Rails provides the rake task `dev:cache` to
 easily toggle caching on/off.
 
 ```bash

guides/source/kindle/toc.html.erb

@@ -14,7 +14,7 @@ Ruby on Rails Guides
         <% if document['work_in_progress']%>(WIP)<% end %>
       </li>
     <% end %>
-  </ul>  
+  </ul>
 <% end %>
 <hr />
 <ul>