Email Invite custodian with wrong text.

[fjavierm]

When the email 'Invite custodian' is sent the recipient can read something like:

Custodian name has created an account for you to manage the

{‘team_id’: 15, ‘created_at’: ‘2017-06-30T15:53:27.207+01:00’, ‘id’: 2, ‘updated_at’: ‘2017-11-20T11:54:36.826+00:00’, ‘key’: ‘country’} register.

Expected result
Register name should be shown.

Actual result
JSON representation of the register is shown.

In addition, we should investigate what happen if the user is invited to more than one register.

• Can a collection be sent as a parameter for the template?
• Do we need to build a comma separated list to send as a String?

Updated: Apparently, after talks with Notify team, arrays are accepted.
Updated: Suggested text:
((current_user_full_name)) has created an account for you to manage the below registers: ((registers))

/cc @Maidment64