Allow custom date range for order type PTK

[linushstge]

Sometimes its necessary to fetch older logs which may already fetched in a previous request. With this improvement the PTK order type supports custom date ranges.

Examples:

// Default: Fetch logs since last fetch
$ptk = $this->client->PTK();

// Fetch logs from -3 hours to now
$ptk = $this->client->PTK(Carbon::now()->subHours(3));

// Fetch logs from -24 hours to -12 hours
$ptk = $this->client->PTK(Carbon::now()->subHours(24), Carbon::now()->subHours(12));

// Fetch logs from yesterday
$ptk = $this->client->PTK(Carbon::now()->subDay()->startOfDay(), Carbon::now()->subDay()->endOfDay());

return $ptk->getData();

[andrew-svirin]

I think that here is another naming.

This naming was before.

   DateTimeInterface $dateTime = null,
        DateTimeInterface $startDateTime = null,
        DateTimeInterface $endDateTime = null

And tests not updated.

[andrew-svirin]

Merged.