'Save an event role invite to database and return accept and decline links.
:param email: Email for the invite
:param role_name: Role name for the invite
:param event_id: Event id'

@staticmethod
def add_event_role_invite(email, role_name, event_id):

    role = Role.query.filter_by(name=role_name).first()
    event = Event.query.get(event_id)
    role_invite = RoleInvite(email=email.lower(), event=event, role=role, created_at=datetime.now())
    hash = random.getrandbits(128)
    role_invite.hash = ('%032x' % hash)
    save_to_db(role_invite, 'Role    Invite    saved')
    accept_link = url_for('events.user_role_invite', event_id=event_id, hash=role_invite.hash)
    decline_link = url_for('events.user_role_invite_decline', event_id=event_id, hash=role_invite.hash)
    return (accept_link, decline_link)
