Fix ActiveRecord::Migration deprecations

Extending from ActiveRecord::Migration is deprecated, but was still used
in a bunch of places.

1 files changed, 2 insertions, 2 deletions

diff --git a/doc/development/background_migrations.md b/doc/development/background_migrations.md
index bb9a296ef12..dd4a9e058d7 100644
--- a/doc/development/background_migrations.md
+++ b/doc/development/background_migrations.md
@@ -211,7 +211,7 @@ existing data. Since we're dealing with a lot of rows we'll schedule jobs in
 batches instead of doing this one by one:
 
 ```ruby
-class ScheduleExtractServicesUrl < ActiveRecord::Migration
+class ScheduleExtractServicesUrl < ActiveRecord::Migration[4.2]
   disable_ddl_transaction!
 
   class Service < ActiveRecord::Base
@@ -242,7 +242,7 @@ jobs and manually run on any un-migrated rows. Such a migration would look like
 this:
 
 ```ruby
-class ConsumeRemainingExtractServicesUrlJobs < ActiveRecord::Migration
+class ConsumeRemainingExtractServicesUrlJobs < ActiveRecord::Migration[4.2]
   disable_ddl_transaction!
 
   class Service < ActiveRecord::Base