[COMMON] Delete data_frame transforms also in between individual tests

Author: estolfo

elasticsearch-xpack/spec/xpack/rest_api_yaml_spec.rb

@@ -61,6 +61,7 @@
               Elasticsearch::RestAPIYAMLTests::TestFile.send(:clear_rollup_jobs, ADMIN_CLIENT)
               Elasticsearch::RestAPIYAMLTests::TestFile.send(:clear_machine_learning_indices, ADMIN_CLIENT)
               Elasticsearch::RestAPIYAMLTests::TestFile.send(:clear_indices, ADMIN_CLIENT)
+              Elasticsearch::RestAPIYAMLTests::TestFile.send(:clear_data_frame_transforms, ADMIN_CLIENT)
               test_file.setup(ADMIN_CLIENT)
             end