Removed anonymous function to support PHP 5.2

main/mashape/http/UrlUtils.php

@@ -32,7 +32,15 @@ class UrlUtils {
 			$parameters = array();
 		}
 		// Remove null parameters
-        $parameters = array_filter($parameters, function($value) { return !is_null($value); });
+		$keys = array_keys($parameters);
+		for ($i = 0;$i<count($keys);$i++) {
+			$key = $keys[$i];
+			if ($parameters[$key] === null) {
+				unset($parameters[$key]);
+			} else {
+				$parameters[$key] = (string)$parameters[$key];
+			}
+		}
 
 		$finalUrl = $url;
 		$matches = null;