The `zipball_url` and `tarball_url` fields on the Release API payload
always link to "legacy" archives that are of a different format than
those one would get if they downloaded an archive from a Release using
the web interface. The GitHub API does not seem to publish links to
non-legacy archives.
This adds a redirect hack to turn "legacy" Codeload URLs into non-legacy
ones with the goal of ensuring the consistency of user experience when
downloading archives.
