Extract constants in 20180430143705_backfill_runner_type_for_ci_runners_post_migrate

db/post_migrate/20180430143705_backfill_runner_type_for_ci_runners_post_migrate.rb

@@ -3,14 +3,17 @@ class BackfillRunnerTypeForCiRunnersPostMigrate < ActiveRecord::Migration
 
   DOWNTIME = false
 
+  PROJECT_RUNNER_TYPE = 1
+  INSTANCE_RUNNER_TYPE = 3
+
   disable_ddl_transaction!
 
   def up
-    update_column_in_batches(:ci_runners, :runner_type, 1) do |table, query|
+    update_column_in_batches(:ci_runners, :runner_type, PROJECT_RUNNER_TYPE) do |table, query|
       query.where(table[:is_shared].eq(true)).where(table[:runner_type].eq(nil))
     end
 
-    update_column_in_batches(:ci_runners, :runner_type, 3) do |table, query|
+    update_column_in_batches(:ci_runners, :runner_type, INSTANCE_RUNNER_TYPE) do |table, query|
       query.where(table[:is_shared].eq(false)).where(table[:runner_type].eq(nil))
     end
   end