Update nitrokey crate to 0.2.3

This change updates the nitrokey crate to version 0.2.3. This version
bumps the rand crate used to 0.6.1, which in turn requires an additional
set of dependencies.

Import subrepo nitrokey/:nitrokey at b3e2adc5bb1300441ca74cc7672617c042f3ea31
Import subrepo rand/:rand at 73613ff903512e9503e41cc8ba9eae76269dc598
Import subrepo rustc_version/:rustc_version at 0294f2ba2018bf7be672abd53db351ce5055fa02
Import subrepo semver-parser/:semver-parser at 750da9b11a04125231b1fb293866ca036845acee
Import subrepo semver/:semver at 5eb6db94fa03f4d5c64a625a56188f496be47598

1 files changed, 84 insertions, 108 deletions

diff --git a/rand/README.md b/rand/README.md
index f72bd51..95970af 100644
--- a/rand/README.md
+++ b/rand/README.md
@@ -1,12 +1,28 @@
-rand
-====
+# Rand
 
-A Rust library for random number generators and other randomness functionality.
+[![Build Status](https://travis-ci.org/rust-random/rand.svg?branch=master)](https://travis-ci.org/rust-random/rand)
+[![Build Status](https://ci.appveyor.com/api/projects/status/github/rust-random/rand?svg=true)](https://ci.appveyor.com/project/rust-random/rand)
+[![Crate](https://img.shields.io/crates/v/rand.svg)](https://crates.io/crates/rand)
+[![Book](https://img.shields.io/badge/book-master-yellow.svg)](https://rust-random.github.io/book/)
+[![API](https://img.shields.io/badge/api-master-yellow.svg)](https://rust-random.github.io/rand)
+[![API](https://docs.rs/rand/badge.svg)](https://docs.rs/rand)
+[![Minimum rustc version](https://img.shields.io/badge/rustc-1.22+-lightgray.svg)](https://github.com/rust-random/rand#rust-version-requirements)
 
-[![Build Status](https://travis-ci.org/rust-lang-nursery/rand.svg?branch=master)](https://travis-ci.org/rust-lang-nursery/rand)
-[![Build status](https://ci.appveyor.com/api/projects/status/rm5c9o33k3jhchbw?svg=true)](https://ci.appveyor.com/project/alexcrichton/rand)
+A Rust library for random number generation.
+
+Rand provides utilities to generate random numbers, to convert them to useful
+types and distributions, and some randomness-related algorithms.
+
+The core random number generation traits of Rand live in the [rand_core](
+https://crates.io/crates/rand_core) crate but are also exposed here; RNG
+implementations should prefer to use `rand_core` while most other users should
+depend on `rand`.
+
+Documentation:
+-   [The Rust Rand Book](https://rust-random.github.io/book)
+-   [API reference (master)](https://rust-random.github.io/rand)
+-   [API reference (docs.rs)](https://docs.rs/rand)
 
-[Documentation](https://docs.rs/rand)
 
 ## Usage
 
@@ -14,126 +30,86 @@ Add this to your `Cargo.toml`:
 
 ```toml
 [dependencies]
-rand = "0.4"
+rand = "0.6"
 ```
 
-and this to your crate root:
+To get started using Rand, see [The Book](https://rust-random.github.io/book).
 
-```rust
-extern crate rand;
-```
 
-### Versions
+## Versions
 
-Version `0.4`was released in December 2017. It contains almost no breaking
-changes since the `0.3` series, but nevertheless contains some significant
-new code, including a new "external" entropy source (`JitterRng`) and `no_std`
-support.
+The Rand lib is not yet stable, however we are careful to limit breaking changes
+and warn via deprecation wherever possible. Patch versions never introduce
+breaking changes. The following minor versions are supported:
 
-Version `0.5` is in development and contains significant performance
-improvements for the ISAAC random number generators.
+-   Version 0.6 was released in November 2018, redesigning the `seq` module,
+    moving most PRNGs to external crates, and many small changes.
+-   Version 0.5 was released in May 2018, as a major reorganisation
+    (introducing `RngCore` and `rand_core`, and deprecating `Rand` and the
+    previous distribution traits).
+-   Version 0.4 was released in December 2017, but contained almost no breaking
+    changes from the 0.3 series.
 
-## Examples
+A detailed [changelog](CHANGELOG.md) is available.
 
-There is built-in support for a random number generator (RNG) associated with each thread stored in thread-local storage. This RNG can be accessed via thread_rng, or used implicitly via random. This RNG is normally randomly seeded from an operating-system source of randomness, e.g. /dev/urandom on Unix systems, and will automatically reseed itself from this source after generating 32 KiB of random data.
+When upgrading to the next minor series (especially 0.4 → 0.5), we recommend
+reading the [Upgrade Guide](https://rust-random.github.io/book/update.html).
 
-```rust
-let tuple = rand::random::<(f64, char)>();
-println!("{:?}", tuple)
-```
+### Rust version requirements
 
-```rust
-use rand::Rng;
+Since version 0.5, Rand requires **Rustc version 1.22 or greater**.
+Rand 0.4 and 0.3 (since approx. June 2017) require Rustc version 1.15 or
+greater. Subsets of the Rand code may work with older Rust versions, but this
+is not supported.
 
-let mut rng = rand::thread_rng();
-if rng.gen() { // random bool
-    println!("i32: {}, u32: {}", rng.gen::<i32>(), rng.gen::<u32>())
-}
-```
+Travis CI always has a build with a pinned version of Rustc matching the oldest
+supported Rust release. The current policy is that this can be updated in any
+Rand release if required, but the change must be noted in the changelog.
 
-It is also possible to use other RNG types, which have a similar interface. The following uses the "ChaCha" algorithm instead of the default.
+To avoid bumping the required version unnecessarily, we use a `build.rs` script
+to auto-detect the compiler version and enable certain features or change code
+paths automatically. Since this makes it easy to unintentionally make use of
+features requiring a more recent Rust version, we recommend testing with a
+pinned version of Rustc if you require compatibility with a specific version.
 
-```rust
-use rand::{Rng, ChaChaRng};
+## Crate Features
 
-let mut rng = rand::ChaChaRng::new_unseeded();
-println!("i32: {}, u32: {}", rng.gen::<i32>(), rng.gen::<u32>())
-```
-
-## Features
-
-By default, `rand` is built with all stable features available. The following
+Rand is built with only the `std` feature enabled by default. The following
 optional features are available:
 
--   `i128_support` enables support for generating `u128` and `i128` values
--   `nightly` enables all unstable features (`i128_support`)
--   `std` enabled by default; by setting "default-features = false" `no_std`
-    mode is activated; this removes features depending on `std` functionality:
-    
-        -   `OsRng` is entirely unavailable
-        -   `JitterRng` code is still present, but a nanosecond timer must be
-            provided via `JitterRng::new_with_timer`
-        -   Since no external entropy is available, it is not possible to create
-            generators with fresh seeds (user must provide entropy)
-        -   `thread_rng`, `weak_rng` and `random` are all disabled
-        -   exponential, normal and gamma type distributions are unavailable
-            since `exp` and `log` functions are not provided in `core`
-        -   any code requiring `Vec` or `Box`
--   `alloc` can be used instead of `std` to provide `Vec` and `Box`
-
-## Testing
-
-Unfortunately, `cargo test` does not test everything. The following tests are
-recommended:
-
-```
-# Basic tests for rand and sub-crates
-cargo test --all
-
-# Test no_std support (build only since nearly all tests require std)
-cargo build --all --no-default-features
-
-# Test 128-bit support (requires nightly)
-cargo test --all --features nightly
-
-# Benchmarks (requires nightly)
-cargo bench
-# or just to test the benchmark code:
-cargo test --benches
-```
-
-# `derive(Rand)`
-
-You can derive the `Rand` trait for your custom type via the `#[derive(Rand)]`
-directive. To use this first add this to your Cargo.toml:
-
-```toml
-rand = "0.4"
-rand_derive = "0.3"
-```
-
-Next in your crate:
-
-```rust
-extern crate rand;
-#[macro_use]
-extern crate rand_derive;
-
-#[derive(Rand, Debug)]
-struct MyStruct {
-    a: i32,
-    b: u32,
-}
-
-fn main() {
-    println!("{:?}", rand::random::<MyStruct>());
-}
-```
+- `alloc` can be used instead of `std` to provide `Vec` and `Box`.
+- `log` enables some logging via the `log` crate.
+- `nightly` enables all unstable features (`simd_support`).
+- `serde1` enables serialization for some types, via Serde version 1.
+- `simd_support` enables uniform sampling of SIMD types (integers and floats).
+- `stdweb` enables support for `OsRng` on `wasm32-unknown-unknown` via `stdweb`
+  combined with `cargo-web`.
+- `wasm-bindgen` enables support for `OsRng` on `wasm32-unknown-unknown` via
+  [`wasm-bindgen`]
+
+[`wasm-bindgen`]: https://github.com/rustwasm/wasm-bindgen
+
+`no_std` mode is activated by setting `default-features = false`; this removes
+functionality depending on `std`:
+
+- `thread_rng()`, and `random()` are not available, as they require thread-local
+  storage and an entropy source.
+- `OsRng` and `EntropyRng` are unavailable.
+- `JitterRng` code is still present, but a nanosecond timer must be provided via
+  `JitterRng::new_with_timer`
+- Since no external entropy is available, it is not possible to create
+  generators with fresh seeds using the `FromEntropy` trait (user must provide
+  a seed).
+- Several non-linear distributions distributions are unavailable since `exp`
+  and `log` functions are not provided in `core`.
+- Large parts of the `seq`-uence module are unavailable, unless the `alloc`
+  feature is used (several APIs and many implementations require `Vec`).
 
 
 # License
 
-`rand` is primarily distributed under the terms of both the MIT
-license and the Apache License (Version 2.0).
+Rand is distributed under the terms of both the MIT license and the
+Apache License (Version 2.0).
 
-See LICENSE-APACHE, and LICENSE-MIT for details.
+See [LICENSE-APACHE](LICENSE-APACHE) and [LICENSE-MIT](LICENSE-MIT), and
+[COPYRIGHT](COPYRIGHT) for details.