Merge branch 'deprecated-directly-inheriting-migration' into 'master'

Fix deprecation: Directly inheriting from ActiveRecord::Migration is deprecated.

See merge request gitlab-org/gitlab-ce!23884

changelogs/unreleased/deprecated-directly-inheriting-migration.yml

+---
+title: 'Fix deprecation: Directly inheriting from ActiveRecord::Migration is deprecated.'
+merge_request: 23884
+author: Jasper Maes
+type: other

db/migrate/20181123144235_create_suggestions.rb

 # frozen_string_literal: true
 
-class CreateSuggestions < ActiveRecord::Migration
+class CreateSuggestions < ActiveRecord::Migration[5.0]
   DOWNTIME = false
 
   def change