/**
* @return JSON with reagents list which expiration date is closer than one week.
*/
public function getCloseToExpirationDate()
{
$date = new \DateTime();
$date->add(new \DateInterval('P7D'));
$date = $date->format('Y-m-d');
$odczynniki = Odczynnik::where('data_waznosci', '<=', $date)->get();
return response()->json($odczynniki);
}