Update download link to point to wheel file.

Author: waylan

setup.py

@@ -174,7 +174,7 @@ def run(self):
  name='Markdown',
  version=__version__,
  url='https://pythonhosted.org/Markdown/',
- download_url='http://pypi.python.org/packages/source/M/Markdown/Markdown-%s.tar.gz' % __version__,
+ download_url='http://pypi.python.org/packages/source/M/Markdown/Markdown-%s-py2.py3-none-any.whl' % __version__,
  description='Python implementation of Markdown.',
  long_description=long_description,
  author='Manfred Stienstra, Yuri takhteyev and Waylan limberg',