Make it possible to set parent in CI config node

lib/gitlab/ci/config/node/entry.rb

@@ -8,9 +8,9 @@ module Gitlab
         class Entry
           class InvalidError < StandardError; end
 
-          attr_reader :config
-          attr_accessor :description
           attr_writer :key
+          attr_reader :config
+          attr_accessor :parent, :description
 
           def initialize(config)
             @config = config

lib/gitlab/ci/config/node/factory.rb

@@ -32,8 +32,9 @@ module Gitlab
             end
 
             node.new(value).tap do |entry|
-              entry.description = @attributes[:description]
               entry.key = @attributes[:key]
+              entry.parent = @attributes[:parent]
+              entry.description = @attributes[:description]
             end
           end
         end

spec/lib/gitlab/ci/config/node/factory_spec.rb

@@ -5,7 +5,7 @@ describe Gitlab::Ci::Config::Node::Factory do
     let(:factory) { described_class.new(entry_class) }
     let(:entry_class) { Gitlab::Ci::Config::Node::Script }
 
-    context 'when value setting value' do
+    context 'when setting up a value' do
       it 'creates entry with valid value' do
         entry = factory
           .with(value: ['ls', 'pwd'])
@@ -35,9 +35,21 @@ describe Gitlab::Ci::Config::Node::Factory do
           expect(entry.key).to eq 'test key'
         end
       end
+
+      context 'when setting a parent' do
+        let(:parent) { Object.new }
+
+        it 'creates entry with valid parent' do
+          entry = factory
+            .with(value: 'ls', parent: parent)
+            .create!
+
+          expect(entry.parent).to eq parent
+        end
+      end
     end
 
-    context 'when not setting value' do
+    context 'when not setting up a value' do
       it 'raises error' do
         expect { factory.create! }.to raise_error(
           Gitlab::Ci::Config::Node::Factory::InvalidFactory