Drush-error when using field-create
Drush doesn't support field commands for Drupal 8 yet. The error message is caused by the fact that Drupal 8 no longer has a function field_info_field() - see Drupal change record at https://www.drupal.org/node/2260037

Drush issue at https://github.com/drush-ops/drush/issues/230