Auto merge of #3270 - brson:cargo-docs, r=alexcrichton

Revert "Continuously publish Cargo builds"

This reverts commit 7799014dc7330445f62e2f925573ca15dd8e8e03.

Fixes https://github.com/rust-lang/cargo/issues/3269.

The reason doc.crates.io doesn't display correctly is that travis-cargo writes its own index.html that is just a meta-redirect to the api docs, overwriting cargo's own docs.

r? @alexcrichton