[API] Reorganize API spec tests

Author: picandocodigo

elasticsearch-api/lib/elasticsearch/api/actions/security/enroll_node.rb

@@ -23,7 +23,7 @@ module Actions
         #
         # @option arguments [Hash] :headers Custom HTTP headers
         #
-        # @see https://www.elastic.co/guide/en/elasticsearch/reference/master/security-api-enroll-node.html
+        # @see https://www.elastic.co/guide/en/elasticsearch/reference/master/security-api-node-enrollment.html
         #
         def enroll_node(arguments = {})
           headers = arguments.delete(:headers) || {}

elasticsearch-api/lib/elasticsearch/api/actions/terms_enum.rb

@@ -45,7 +45,7 @@ def terms_enum(arguments = {})
                    Elasticsearch::API::HTTP_GET
                  end
 
-        path = "#{Elasticsearch::API::Utils.__listify(_index)}/_terms_enum"
+        path   = "#{Utils.__listify(_index)}/_terms_enum"
         params = {}
 
         body = arguments[:body]

elasticsearch-api/spec/elasticsearch/data_frame/update_data_frame_transform_spec.rb renamed to elasticsearch-api/spec/elasticsearch/api/actions/data_frame/update_data_frame_transform_spec.rb

@@ -18,7 +18,6 @@
 require 'spec_helper'
 
 describe 'client#set_upgrade_mode' do
-
   let(:expected_args) do
     [
        'POST',