def addUser(self, username, password,
                firstname, lastname,
                email, role):
        """adds a user to the invitation list"""
        self._invites.append({
            "username":username,
            "password":password,
            "firstname":firstname,
            "lastname":lastname,
            "fullname":"%s %s" % (firstname, lastname),
            "email":email,
            "role":role
        })
adds a user to the invitation list