In the Understanding Account and Contacts unit (https://developer.salesforce.com/trailhead/en/admin_intro_accounts_contacts/admin_intro_accounts_contacts_relationships)

the challenge asks that you use Related Contacts to add a Contact to multiple Accounts.  This functionality does not appear to be implemented, and I've seen a blog post that says it won't be implemented until the Summer '16 release (which hasn't happened yet).  It won't let me finish the challenge.  Is there any way to complete this challenge?  Am I missing something?

In the Understanding Account and Contacts unit (https://developer.salesforce.com/trailhead/en/admin_intro_accounts_contacts/admin_intro_accounts_contacts_relationships)

the challenge asks that you use Related Contacts to add a Contact to multiple Accounts.  This functionality does not appear to be implemented, and I've seen a blog post that says it won't be implemented until the Summer '16 release (which hasn't happened yet).  It won't let me finish the challenge.  Is there any way to complete this challenge?  Am I missing something?