def do_invite(invite)
      if invite.existing_user?
        deliver_email(InviteMailer.existing_user(invite))
        after_invite_existing_user(invite)
        invite.save
      else
        deliver_email(InviteMailer.new_user(invite))
        after_invite_new_user(invite)
      end
    end
def do_invite(invite)
      if invite.existing_user?
        deliver_email(InviteMailer.existing_user(invite))
        after_invite_existing_user(invite)
        invite.save
      else
        deliver_email(InviteMailer.new_user(invite))
        after_invite_new_user(invite)
      end
    end
Invite user by sending email.
 Existing users are granted permissions via #after_invite_existing_user.
 New users are granted permissions via #after_invite_new_user, currently a null op.