Bump crypto-common and hybrid-array (RustCrypto#1469)

Bumps the following dependencies:

- `block-buffer` => v0.11.0-pre.4
- `block-padding` => v0.4.0-pre.4
- `crypto-common` => v0.2.0-pre.4
- `hybrid-array` => v0.2.0-rc.0
- `inout` => v0.2.0-pre.4

Also prepares the following releases:

- `cipher` v0.5.0-pre.2
- `digest` v0.11.0-pre.4