clippy_utils 0.0.1

This is just a dummy crate to reserve the name clippy_utils. We currently don't plan to publish this crate on crates.io, but we want to keep the option of doing so in the future.

To use this, add clippy_utils as a git dependency:

clippy_utils = { git = "https://github.com/rust-lang/rust-clippy", rev = "<sha>" }