Merge branch 'develop' into release/3.0.0

# Conflicts:
#	CHANGELOG
#	src/codebird.php

Author: mynetx

CHANGELOG

@@ -17,6 +17,7 @@ codebird-php - changelog
 + Fixes for non-multipart media uploads, see #141
 + Return rate-limiting info as object, when return format = object
 + Add unit testing suite
+- #147 Undefined index when checking for possible media files
 
 2.7.2 (2015-09-23)
 - #135 Invalid HTTP request headers in non-cURL mode

src/codebird.php

@@ -1701,7 +1701,7 @@ protected function _getMultipartRequestFromParams($method_template, $border, $pa
    * @return mixed
    */
   protected function _checkForFiles($method_template, $key, $value) {
-    if (!isset(self::$_possible_files[$method_template])
+    if (!array_key_exists($method_template, self::$_possible_files)
       || !in_array($key, self::$_possible_files[$method_template])
     ) {
       return false;