Milestone params missing

[dereuromark]

        /** @var \Github\Api\Repo $repo */
        $repo = $this->gitClient->api('repo');

        $repository = $this->repository;

        return $repo->milestones($this->organization, $repository, ['state' => 'all']);

But:
https://github.com/KnpLabs/php-github-api/blob/master/lib/Github/Api/Repo.php#L596

See:
https://developer.github.com/v3/issues/milestones/#list-milestones-for-a-repository

The default is not all but open, so you can never get the closed ones.

I think the code should be:

    /**
     * @param string $username
     * @param string $repository
     * @param array $parameters
     *
     * @return array
     */
    public function milestones($username, $repository, array $parameters = [])
    {
        return $this->get('/repos/'.rawurldecode($username).'/'.rawurldecode($repository).'/milestones', $parameters);
    }

[acrobat]

Good catch @dereuromark! Can you open a pr for it? Thanks!