Add pipeline stage index column

db/migrate/20180417101940_add_index_to_ci_stage.rb

+class AddIndexToCiStage < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def change
+    add_column :ci_stages, :index, :integer
+  end
+end

db/schema.rb

@@ -486,6 +486,7 @@ ActiveRecord::Schema.define(version: 20180418053107) do
     t.string "name"
     t.integer "status"
     t.integer "lock_version"
+    t.integer "index"
   end
 
   add_index "ci_stages", ["pipeline_id", "name"], name: "index_ci_stages_on_pipeline_id_and_name", unique: true, using: :btree