Merge pull request facebookarchive#110 from philsturgeon/php55

Dont convert CURLFile: Take 2

Author: gfosco

.travis.yml

@@ -2,4 +2,5 @@ language: php
 php:
   - 5.3
   - 5.4
+  - 5.5
 script: phpunit --stderr --bootstrap tests/bootstrap.php tests/tests.php

src/base_facebook.php

@@ -901,7 +901,7 @@ protected function _oauthRequest($url, $params) {
 
     // json_encode all params values that are not strings
     foreach ($params as $key => $value) {
-      if (!is_string($value)) {
+      if (!is_string($value) && !($value instanceof CURLFile)) {
         $params[$key] = json_encode($value);
       }
     }