General improvements (#34)

* Minor improvements

* Fix `Debug` implementation

* Fix de-serialization

* Fix accidental usage of nightly

* Fix MSRV warning

* Replace macro with derive-where

* Add `rust-version` into `Cargo.toml`

* Move Serde trait implementation macro to `serialization` module

* Add ability to test without a Ristretto backend

* Improve docs

* Fix testing multiple backends together

* Implement `Ord` and `PartialOrd`

* `no_std` by default

* Remove unnecessary `doc_cfg`

* Remove dev-dependency on self

* Implement `Ord` and `PartialOrd` for `InternalError`

* Remove base64 encoding for serde

* Only take references

* Remove unnecessary qualifications from super-trait times

src/errors.rs

@@ -12,7 +12,7 @@ use std::error::Error;
 use displaydoc::Display;
 
 /// Represents an error in the manipulation of internal cryptographic data
-#[derive(Clone, Debug, Display, Eq, Hash, PartialEq)]
+#[derive(Clone, Copy, Debug, Display, Eq, Hash, Ord, PartialEq, PartialOrd)]
 pub enum InternalError {
     /// Could not parse byte sequence for key
     InvalidByteSequence,