Redirect for latest download / Download permalinks #13
Description
Would be nice to be able to do something like wget https://yarnpkg.com/latest.tar.gz to get the latest tarball. Server should do a 302 (temporary) redirect to the latest download URL, which I assume we'd continue hosting using Github releases (for example, https://github.com/yarnpkg/yarn/releases/download/v0.13.5/kpm-v0.13.5.tar.gz)
Also ideal would be something like https://yarnpkg.com/releases/0.13.5.tar.gz to download one particular version, so as to not tightly-couple the URL scheme to Github.