Reduce a delay between stage_id scheduled migrations

db/post_migrate/20170628080858_migrate_stage_id_reference_in_background.rb

@@ -16,7 +16,7 @@ class MigrateStageIdReferenceInBackground < ActiveRecord::Migration
 
     Build.where(stage_id: nil).in_batches(of: BATCH_SIZE) do |relation|
       jobs = relation.pluck(:id).map { |id| [MIGRATION, [id]] }
-      schedule = index * 5.minutes
+      schedule = index * 2.minutes
       index += 1
 
       BackgroundMigrationWorker.perform_bulk_in(schedule, jobs)

spec/migrations/migrate_stage_id_reference_in_background_spec.rb

@@ -47,10 +47,10 @@ describe MigrateStageIdReferenceInBackground, :migration, :sidekiq do
       Timecop.freeze do
         migrate!
 
-        expect(described_class::MIGRATION).to be_scheduled_migration(5.minutes, 1)
-        expect(described_class::MIGRATION).to be_scheduled_migration(5.minutes, 2)
-        expect(described_class::MIGRATION).to be_scheduled_migration(10.minutes, 3)
-        expect(described_class::MIGRATION).to be_scheduled_migration(10.minutes, 4)
+        expect(described_class::MIGRATION).to be_scheduled_migration(2.minutes, 1)
+        expect(described_class::MIGRATION).to be_scheduled_migration(2.minutes, 2)
+        expect(described_class::MIGRATION).to be_scheduled_migration(4.minutes, 3)
+        expect(described_class::MIGRATION).to be_scheduled_migration(4.minutes, 4)
         expect(BackgroundMigrationWorker.jobs.size).to eq 5
       end
     end