New lockfile format unsupported

[Nemo157]

Since Rust 1.41 the default lockfile format has been updated. This has been supported since Rust 1.38, but unfortunately cargo-crev is still using cargo v0.38 from Rust 1.37.

Trying to run cargo crev crate verify on a repo using the new format gives

> cargo crev crate verify
Error: failed to parse lock file at: /tmp/tmp.9Ks6bkSzKY/foo/Cargo.lock
  caused by: invalid serialized PackageId for key `package.dependencies`

This should just require updating the cargo dependency version (or switching to cargo-metadata if that provides enough details to get independence from the exact file format, and a reduced build time).

[CAD97]

I should note that this issue is preventing me from publishing reviews of my new crates; I can't even just use an older toolchain, because they require the trait coherence changes from 1.41.

[Nemo157]

As a workaround for now you can use cargo-lock to translate back and forth between the formats.

[dpc]

Anyone can try to bump the cargo dependency and submit a PR?