Move the ee? helper method into the helper

danger/changelog/Dangerfile

@@ -16,16 +16,12 @@ consider adding any of the %<labels>s labels.
 #{SEE_DOC}
 MSG
 
-def ee?
-  ENV['CI_PROJECT_NAME'] == 'gitlab-ee' || File.exist?('../../CHANGELOG-EE.md')
-end
-
 def ee_changelog?(changelog_path)
   changelog_path =~ /unreleased-ee/
 end
 
 def ce_port_changelog?(changelog_path)
-  ee? && !ee_changelog?(changelog_path)
+  helper.ee? && !ee_changelog?(changelog_path)
 end
 
 def check_changelog(path)

danger/plugins/helper.rb

@@ -31,6 +31,11 @@ def all_changed_files
         .sort
     end
 
+    # @return [Boolean]
+    def ee?
+      ENV['CI_PROJECT_NAME'] == 'gitlab-ee' || File.exist?('../../CHANGELOG-EE.md')
+    end
+
     # @return [Hash<String,Array<String>>]
     def changes_by_category
       all_changed_files.inject(Hash.new { |h, k| h[k] = [] }) do |hsh, file|