public function activateUser($email, $activationKey)
    {
        if ($this->validateActivationKey($email, $activationKey)) {
            $user = $this->findByEmailAndActivationKey($email, $activationKey)->first();

            if ($user->active == 0) {
                $user->active = 1;
                $user->activation_key = null;
                if ($this->save($user)) {
                    return true;
                }
            }
        }

        return false;
    }