Updated download_url as from release guidelines.

setup.py

@@ -50,7 +50,7 @@ def configuration(parent_package='', top_path=None):
     maintainer = 'ETS Developers',
     maintainer_email = 'enthought-dev@enthought.com',
     url = 'https://github.com/enthought/scimath',
-    download_url = ('http://www.enthought.com/repo/ets/scimath-%s.tar.gz' %
+    download_url = ('https://github.com/enthought/scimath/archive/%s.tar.gz' %
                     info['__version__']),
     classifiers = [c.strip() for c in """\
         Development Status :: 4 - Beta