Add failure_reason column to ci_pipelines

Conflicts:
	db/schema.rb

db/migrate/20170929080234_add_failure_reason_to_pipelines.rb

+class AddFailureReasonToPipelines < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def change
+    add_column :ci_pipelines, :failure_reason, :integer
+  end
+end

db/schema.rb

@@ -342,6 +342,7 @@ ActiveRecord::Schema.define(version: 20171004121444) do
     t.integer "source"
     t.integer "config_source"
     t.boolean "protected"
+    t.integer "failure_reason"
   end
 
   add_index "ci_pipelines", ["auto_canceled_by_id"], name: "index_ci_pipelines_on_auto_canceled_by_id", using: :btree