resolves issued #172

[Ghostff]

Due to https://bugs.php.net/bug.php?id=69489, PHP 7.1 and above raises a notice. This PR provides two alternatives.

1. Using a flag to suppress the error. (Current default behavior)

$config->setOption('suppress_tmp_warn', true);

2. Explicitly setting a path for unique file creation.

$config->setOption('tmp_path', 'C:\Users\{UserName}\AppData\Local\Temp');

[ConnectGrid]

I created a separate pull-request #271 with an alternate solution.