Update PyPI root for dependency links. Fixes #827.

CHANGES.rst

@@ -5,6 +5,8 @@ CHANGES
 v28.7.1
 -------
 
+* #827: Update PyPI root for dependency links.
+
 * #833: Backed out changes from #830 as the implementation
   seems to have problems in some cases.
 

setup.py

@@ -77,7 +77,7 @@ def pypi_link(pkg_filename):
     Given the filename, including md5 fragment, construct the
     dependency link for PyPI.
     """
-    root = 'https://pypi.python.org/packages/source'
+    root = 'https://files.pythonhosted.org/packages/source'
     name, sep, rest = pkg_filename.partition('-')
     parts = root, name[0], name, pkg_filename
     return '/'.join(parts)