Merge pull request #259 from ankadada/master

make http response header words in title case

Author: jemygraw

src/Qiniu/Http/Client.php

@@ -129,6 +129,7 @@ private static function parseHeaders($raw)
             $headerLine = trim($line);
             $kv = explode(':', $headerLine);
             if (count($kv) > 1) {
+                $kv[0] = ucwords($kv[0], '-');
                 $headers[$kv[0]] = trim($kv[1]);
             }
         }