Migrate: Duplicate key "created" - Data Story Migration

Problem/Motivation

drush migrate:import --group=ekan results in error:

 The /.../web/profiles/contrib/ekan/modules/ekan_migrate/migrations
  /ekan_data_story.yml contains invalid YAML
 Duplicate key "created" detected at line 39 (near "created: created").

Steps to reproduce

Install ekan
enable ekan_migrate
start migration by drush migrate:import --group=ekan

Proposed resolution

remove duplicate keys in migration .yml

Remaining tasks

test

User interface changes

n/a

API changes

n/a

Data model changes

n/a