pin clippy version number to rustc version number?

[matthiaskrgr]

Clippy has been on version 0.0.212 for quite some time now, and the version number has become quite irrelevant now that we always ship a -git version with nightly/beta/stable.

Should we pin the clippy to the respective rustc version like cargo does?
cargo 0.49.0 corresponds to rustc 1.49.0.
Equally, we could bump clippy to 0.1.49 for beta, and 0.1.50 for nightly.

[flip1995]

I'm in favor of this

cc @rust-lang/clippy

[Manishearth]

+1