A cargo subcommand for displaying when Rust dependencies are out of date.

cargo-outdated is for displaying when dependencies have newer versions
available.

The functionality of cargo-outdated largely depends on the cargo builtin
command cargo update.

To retrieve the list of available SemVer compatible dependencies,
cargo-outdated firstly creates a temporary workspace, then executes cargo
update against it, finally compares the temporary dependency tree with the
original one.

Similarly, to check the latest dependencies, cargo-outdated replaces the SemVer
requirements of direct dependencies with wildcards then goes through the same
process.