README.rst: Update Static URL (point to PyPI)

  $ wget -S http://lukearno.com/projects/static/
  ...
  HTTP request sent, awaiting response...
    HTTP/1.1 404 Not Found
    ...
  2013-09-20 07:53:36 ERROR 404: Not Found.

PyPI still points to lukearno.com as the home page, but we can expect
the PyPI URL to age better.
Merge pull request #14 from wking/update-static-url

README.rst: Update Static URL (point to PyPI)