Creating a user fails if the username is not a valid email address

[daniellienert]

./flow sandstormuser:listusers
+-------+------+---------+
| Email | Name | Role(s) |
+-------+------+---------+
  0 users total.
vagrant@punktde:/var/www % ./flow sandstormuser:create
Please specify the required argument "username": test
Please specify the required argument "password": test
An instance of "Sandstorm\UserManagement\Domain\Model\RegistrationFlow" failed to pass validation with 1 error(s):
email:
Please specify a valid email address.

  Type: Neos\Flow\Persistence\Exception\ObjectValidationFailedException
  Code: 1322585164
  File: Data/Temporary/Development/Cache/Code/Flow_Object_Classes/Neos_Flow_Persist
        ence_Doctrine_PersistenceManager.php
  Line: 137

Open Data/Logs/Exceptions/201710251724338f8d5f.txt for a full stack trace.