Alow Mutating Entry keys and iterator keys #358

Job	Run time
Check MSRV and minimal-versions	2m 43s
nostd_build (1.63.0, thumbv6m-none-eabi)	37s
miri	3m 31s
nostd_build (stable, thumbv6m-none-eabi)	17s
clippy	16s
tests (1.63.0)	1m 5s
tests (stable, arbitrary)	37s
tests (stable, quickcheck)	42s
tests (stable, rayon)	48s
tests (stable, rustc-rayon)	48s
tests (stable, serde)	1m 7s
tests (stable, borsh)	39s
tests (stable, std)	37s
tests (beta)	37s
tests (nightly, test build benchmarks)	36s
Success	1s
	15m 1s

Provide feedback