General improvements (#250)

* Remove unnecessary constraints on hash

* Remove unnecessary `Result` on `KeyPair::generate_random`

* Fix de-serialization issue on `Ke1State`

* Fix rustfmt

* Remove allocations in `envelope`

* Run Clippy for tests and rustdoc lints too

* Fix `Debug` implementation

* Fix missing constraints on `ClientRegistration`

* Fix de-serialization

* Pin temporary dependency

* Update dependencies

* Replace macro with derive-where

* Remove unnecessary installation of Rust components

* Improve macro naming

* Implement `Copy`, `Debug`, `Ord` and `PartialOrd` for high-level items

* Add `rust-version` field to `Cargo.toml`

* Remove unnecessary allocations

* Fix MSRV

* Fix no_std

* Remove unnecessary allocations

* Remove unnecessary allocations

* Not importing items from voprf helps readability

* Fix rustdoc

* Remove unnecessary allocations

* Remove unnecessary allocations

* Replace `Vec` from `diffie_hellman` with `GenericArray`

* Remove unnecessary allocations

* Remove unnecessary allocations

* Remove `cfg(feature = bench)` guard for `missing_docs`

* Fix documentation

* Remove all remaining allocations from `KeyExchange`

* Improve type-safety

* Remove all remaining allocations in `keypair`

* Remove last remaining allocations except `NonVerifiableClient` input

* Remove base64 encoding in Serde implementation

* Remove unnecessary Serde `alloc` feature

* Make curve25519-dalek optional

* Rename `serialize` crate feature to `serde`

* Switch `KeGroup` implementations to higher-level libraries

- Fixes missing clamping in X25519
- X25519 is now a separate crate feature

* Fix typo

src/tests/parser.rs

@@ -21,7 +21,7 @@ fn parse_vector_types(input: &str) -> String {
     for caps in re.captures_iter(input) {
         let vector_type = format!(
             "\"{}\": [\n {} \n]",
-            caps["type"].to_string(),
+            &caps["type"],
             parse_ciphersuites(chunks[count])
         );
         vector_types.push(vector_type);
@@ -44,8 +44,8 @@ fn parse_ciphersuites(input: &str) -> String {
     for caps in re.captures_iter(input) {
         let ciphersuite = format!(
             "{{ \"{}, {}\": {{ {} }} }}",
-            caps["group"].to_string(),
-            caps["hash"].to_string(),
+            &caps["group"],
+            &caps["hash"],
             parse_params(chunks[count])
         );
         ciphersuites.push(ciphersuite);