"cargo update" should say what happened

[sfackler]

If my Cargo.lock has me pinned to e.g. openssl:0.1.0, and I run cargo update -p openssl, all I see is

.. ❯ cargo update -p openssl
    Updating registry `https://github.com/rust-lang/crates.io-index`

It turns out that it bumped the version to 0.1.1, but I have no way of knowing that without looking in the lockfile or building and seeing what version pops up there. It'd be nice if it had some output like

.. ❯ cargo update -p openssl
    Updating registry `https://github.com/rust-lang/crates.io-index`
    Updating openssl-sys 0.1.0 -> 0.1.1
    Updating openssl 0.1.0 -> 0.1.1