Change effective on 29 September 2016
The Heroku Toolbelt CLI command
members:add now sends an invitation e-mail to the account specified to join your Heroku Team.
$ heroku members:add firstname.lastname@example.org --role role-type -o team-name Inviting email@example.com to team-name as role-type... email sent
Note that in order to revoke an existing invite, you’ll need to use the Heroku Teams overview page in the Heroku Dashboard (web UI).
For more information on the members:add CLI command, you can invoke the CLI help:
$ heroku help members:add