feature KnpLabs#1020 Branch lists . ( ? query per_page) (pitonic)

This PR was squashed before being merged into the 3.4.x-dev branch.

Discussion
----------

For function "branches"  added: parameters for the query string.
example to use:
``` 
return $this->client->api('repo')->branches($this->id, $repo, null , [ 'page' =>2, 'per_page' => 100 ]);
```

Commits
-------

ab3d87b added: parameters for the query string
44c3923 fixed formating

Author: pitonic

lib/Github/Api/Repo.php

@@ -503,17 +503,18 @@ public function statuses()
      * @param string $username   the username
      * @param string $repository the name of the repository
      * @param string $branch     the name of the branch
+     * @param array  $parameters parameters for the query string
      *
      * @return array list of the repository branches
      */
-    public function branches($username, $repository, $branch = null)
+    public function branches($username, $repository, $branch = null, array $parameters = [])
     {
         $url = '/repos/'.rawurlencode($username).'/'.rawurlencode($repository).'/branches';
         if (null !== $branch) {
             $url .= '/'.rawurlencode($branch);
         }
 
-        return $this->get($url);
+        return $this->get($url, $parameters);
     }
 
     /**