catch RejectedItemExceptions and log them instead of stopping the pipeline

[clemzarch]

avant:

public function transform() : \Generator
{
    $line = yield;
    do {
        $line = ($this->mapper)($line, $line);
    } while ($line = (yield new \Kiboko\Component\Bucket\AcceptanceResultBucket($line)));
    (yield new \Kiboko\Component\Bucket\AcceptanceResultBucket($line));
}

après:

public function transform() : \Generator
{
    $input = yield;
    while ($input !== null) {
        try {
            $line = ($this->mapper)($input, $input);
        } catch (\Kiboko\Contract\Pipeline\RejectedItemException $exception) {
            $this->logger->error($exception->getMessage(), array('input' => $input));
            $input = (yield new \Kiboko\Component\Bucket\RejectionResultBucket($input));
            continue;
        }
        $input = (yield new \Kiboko\Component\Bucket\AcceptanceResultBucket($line));
    }
    (yield new \Kiboko\Component\Bucket\AcceptanceResultBucket($input));
}