Be more precise in recognising three-part curl response (#102)

* Be more precise in recognising three-part curl response

* Split the recognition of a three part response from picking the correct bits out of the result array. Use strict checking for type safety.

Author: driehuis

src/MessageBird/Common/HttpClient.php

@@ -219,7 +219,8 @@ public function performHttpRequest($method, $resourceName, $query = null, $body
 
         // Split the header and body
         $parts = explode("\r\n\r\n", $response, 3);
-        list($responseHeader, $responseBody) = ($parts[0] === 'HTTP/1.1 100 Continue') ? array ($parts[1], $parts[2]) : array ($parts[0], $parts[1]);
+        $isThreePartResponse = (strpos($parts[0], "\n") === false && strpos($parts[0], 'HTTP/1.') === 0);
+        list($responseHeader, $responseBody) = $isThreePartResponse ? array ($parts[1], $parts[2]) : array ($parts[0], $parts[1]);
 
         curl_close($curl);