cargo-msrv v0.16.0-beta.1

(Changelog for 0.16.0 is in progress, and may be incomplete)

Added

• Subcommand cargo msrv verify now supports setting a custom Rust version via the --rust-version <VERSION> argument,
  which can be used to check for a crate's compatibility against a specific Rust version.
• Added flag --write-msrv to cargo msrv (find), which upon finding the MSRV writes its value to the Cargo manifest.
• Added option to refer to a specific crate using its Cargo manifest (with --manifest-path) instead of its path (with --path)
• Added a 'minimal' output option intended for machine-readable use when full json output is undesirable.

Changed

• CLI options are now grouped.
• Option --min <version> now also accepts two component semver major.minor versions, in addition to full three component (strict) SemVer versions, and edition specifiers like "2015", "2018" and "2021".
• Option --max <version> now also accepts two component semver major.minor versions, in addition to full three component (strict) SemVer versions.
• The rust-releases index is now only fetched for subcommands which depend on it.
• Renamed --toolchain-file to --write-toolchain-file to emphasise that the toolchain-file is an output.
• Subcommand cargo msrv set will now default to writing a regular TOML table for the metadata MSRV fallback value, instead of an inline table.
• The rust-toolchain file will now be overwritten if a rust-toolchain file was already present.

Fixed

• Subcommand cargo msrv set will now return an error when the Cargo manifest solely consists of a virtual workspace.
• The program will no longer return an unformatted message when a command failed and the output format was set to json.
• Fix issue where reading the fallback MSRV from a TOML inline table was not possible.
• Fix an index out-of-bounds panic which occurred if the filtered Rust releases search space was empty