Bump most dependencies (#1268)

* Bump most dependencies

This actually builds 😊.

* Bump all dependencies

Includes the excellent work of @rschulman in #1265.

* Remove use of ed25519-dalek fork

* Monomorphize more dependencies

* Add compatibility hack for rand

Cargo allows a crate to depend on multiple versions of another, but
`cargo-web` panics in that situation.  Use a wrapper crate to work
around the panic.

* Use @tomaka’s idea for using a newer `rand`

instead of my own ugly hack.

* Switch to Parity master

as its dependency-bumping PR has been merged.

* Update some depenendencies again

* Remove unwraps and `#[allow(deprecated)]`.

* Remove spurious changes to dependencies

Bumping minor or patch versions is not needed, and increases likelyhood
of merge conflicts.

* Remove some redundant Cargo.toml changes

* Replace a retry loop with an expect

`ed25519::SecretKey::from_bytes` will never fail for 32-byte inputs.

* Revert changes that don’t belong in this PR

protocols/noise/src/protocol.rs

@@ -252,4 +252,3 @@ impl rand::RngCore for Rng {
 impl rand::CryptoRng for Rng {}
 
 impl snow::types::Random for Rng {}
-