Support PHP wrappers (e.g. data://) (#72)

* drop use of is_readable which isn't compatible with wrappers (https://www.php.net/manual/en/wrappers.php).

* check stream instead of file

src/ClamavValidator/ClamavValidator.php

@@ -72,18 +72,18 @@ public function validateClamav(string $attribute, $value, array $parameters): bo
 	protected function validateFileWithClamAv($value): bool
     {
         if (is_resource($value)) {
-            $file = $value;
+            $stream = $value;
         } else {
             $file = $this->getFilePath($value);
-            if (! is_readable($file)) {
+            $stream = fopen($file, 'rb');
+            if ($stream === false) {
                 throw ClamavValidatorException::forNonReadableFile($file);
             }
         }
 
         try {
             $socket = $this->getClamavSocket();
             $scanner = $this->createQuahogScannerClient($socket);
-            $stream = is_resource($file) ? $file : fopen($file, 'rb');
             $result = $scanner->scanResourceStream($stream);
         } catch (Exception $exception) {
             if (Config::get('clamav.client_exceptions')) {