`binstalk-downloader` contains stuff about http(s) before the
git code is moved into it and now it becomes http and git.
While git indeed uses http stuff, which is why I decided to put
it into binstalk-downloader, it is more than just downloading
since it is stateful (can be cached locally and updated)
where as http is stateless.
Also `binstalk-downloader`'s codegen time now increases
dramatically and it also creates extra dependencies for
binstalk-fetchers, delaying its execution.
The git code also don't use anything from `binstalk-downloader`
at all, it makes sense to be an independent crate.
Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>
