py-graphviz: updated to 0.10.1

Version 0.10.1
--------------
Fix broken renderer argument in pipe() method and function.

Version 0.10
------------
Add format argument to Graph/Digraph.render(). This follows stand-alone
render() function and mirrors the Graph/Digraph.pipe() method (usually,
format is set on the instance).

Add renderer and formatter arguments to Graph/Digraph.render() and
pipe() methods, as well as stand-alone render() and pipe() functions.


(adam)