Add mimetype support to compare() so diff/patches can be fetched

Author: skwashd

lib/Github/Api/Repository/Commits.php

@@ -15,9 +15,13 @@ public function all($username, $repository, array $params)
         return $this->get('repos/'.rawurlencode($username).'/'.rawurlencode($repository).'/commits', $params);
     }
 
-    public function compare($username, $repository, $base, $head)
+    public function compare($username, $repository, $base, $head, $mediaType = NULL)
     {
-        return $this->get('repos/'.rawurlencode($username).'/'.rawurlencode($repository).'/compare/'.rawurlencode($base).'...'.rawurlencode($head));
+        $headers = array();
+        if (NULL !== $mediaType) {
+            $headers['Accept'] = $mediaType;
+        }
+        return $this->get('repos/'.rawurlencode($username).'/'.rawurlencode($repository).'/compare/'.rawurlencode($base).'...'.rawurlencode($head), array(), $headers);
     }
 
     public function show($username, $repository, $sha)