Website redeploy fails

[Mark-Simulacrum]

I think #98 has been consistently failing for the last several weeks:

Error: {"message":"Not Found","documentation_url":"https://docs.github.com/rest/apps/apps#get-a-repository-installation-for-the-authenticated-app","status":"404"}
Caused by:
    missing field `id` at line 1 column 155

Not sure as to the root cause, but filing so we can track.

cc @Kobzol

[Kobzol]

Right, I think it's because the GH token that is used to run promote-release (a GitHub App, perhaps?) is not installed in the website repository. Can you install it there?

[marcoieni]

Added the www.rust-lang.org repository to the promote-release github app

Proof:

[Kobzol]

Thanks! If this code is exercised in nightly (?), we should see it in tomorrow's logs, I suppose.