Use this Automation Runbook to create Azure AD Users in a really easy way. The runbook relies on the Msonline PowerShell modules which needs to be imported as Azure Automation assets before you can execute the runbook.
See my blog post at http://blog.orneling.se/2015/11/import-new-modules-into-azure-automation/ for more information on how to import these modules into Azure Automation.
A complete setup guide for this runbook is to be found at http://blog.orneling.se/2015/11/create-azure-ad-users-with-azure-automation