Arcyd: Fix smoke tests

[cs-shadow]

smoke-tests fail are flaky and often fail on local machines. Following error message is thrown by phabricator:

You can not access the user inside the implementation of a  method which does not require authentication (as per shouldRequireAuthentication()).'

The error is probably by virtue of arcyd running in a multiprocess environment because arcyon works fine when ran as a single process but fails when several instances are ran together in parallel.