curve,ed: Update digest and sha2 deps

[rozbb]

The build is currently broken

error[E0432]: unresolved import `digest::crypto_common`
   --> curve25519-dalek/src/edwards.rs:109:65
    |
109 |     FixedOutput, HashMarker, array::typenum::U64, consts::True, crypto_common::BlockSizeUser,
    |                                                                 ^^^^^^^^^^^^^ could not find `crypto_common` in `digest`

This is because there was a breaking change between digest 0.11.0-rc.8 and 0.11.0-rc.11.

[tarcieri]

Would be good to bump sha2 to v0.11.0-rc.5 too... and do the same for ed25519-dalek

[rozbb]

Done. I also just checked in a freshly updated Cargo.lock

[tarcieri]

Awesome! Too bad Actions seems to be horribly broken right now

[nabetti1720]

We would like to thank everyone involved for their dedicated efforts. :)
By the way, are you planning to release a new version soon?

RustCrypto/rustls-rustcrypto#112
It's probably blocked by this issue, so as soon as a new version is released we can move forward.

[tarcieri]

@nabetti1720 it's blocked on new releases of the @RustCrypto crates like digest, sha2, and signature, and this: zkcrypto/ff#149