Use Ci config validation helpers only where needed

lib/ci/gitlab_ci_yaml_processor.rb

@@ -2,7 +2,7 @@ module Ci
   class GitlabCiYamlProcessor
     class ValidationError < StandardError; end
 
-    include Gitlab::Ci::Config::ValidationHelpers
+    include Gitlab::Ci::Config::Node::ValidationHelpers
 
     DEFAULT_STAGES = %w(build test deploy)
     DEFAULT_STAGE = 'test'

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

@@ -3,6 +3,8 @@ module Gitlab
     class Config
       module Node
         class BeforeScript < Entry
+          include ValidationHelpers
+
           def keys
             {}
           end

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

@@ -3,8 +3,6 @@ module Gitlab
     class Config
       module Node
         class Entry
-          include Config::ValidationHelpers
-
           attr_reader :value, :nodes, :parent
 
           def initialize(value, root = nil, parent = nil)

lib/gitlab/ci/config/validation_helpers.rb → lib/gitlab/ci/config/node/validation_helpers.rb

 module Gitlab
   module Ci
     class Config
+      module Node
         module ValidationHelpers
           private
 
@@ -23,4 +24,5 @@ module Gitlab
         end
       end
     end
+  end
 end