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, 103 insertions, 0 deletions

diff --git a/semver/README.md b/semver/README.md
new file mode 100644
index 0000000..2a5306d
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+++ b/semver/README.md
@@ -0,0 +1,103 @@
+semver
+======
+
+Semantic version parsing and comparison.
+
+[![Build Status](https://api.travis-ci.org/steveklabnik/semver.svg?branch=master)](https://travis-ci.org/steveklabnik/semver)
+
+[Documentation](https://steveklabnik.github.io/semver)
+
+Semantic versioning (see http://semver.org/) is a set of rules for
+assigning version numbers.
+
+## SemVer and the Rust ecosystem
+
+Rust itself follows the SemVer specification, as does its standard libraries. The two are
+not tied together.
+
+[Cargo](https://crates.io), Rust's package manager, uses SemVer to determine which versions of
+packages you need installed.
+
+## Installation
+
+To use `semver`, add this to your `[dependencies]` section:
+
+```toml
+semver = "0.7.0"
+```
+
+And this to your crate root:
+
+```rust
+extern crate semver;
+```
+
+## Versions
+
+At its simplest, the `semver` crate allows you to construct `Version` objects using the `parse`
+method:
+
+```rust
+use semver::Version;
+
+assert!(Version::parse("1.2.3") == Ok(Version {
+   major: 1,
+   minor: 2,
+   patch: 3,
+   pre: vec!(),
+   build: vec!(),
+}));
+```
+
+If you have multiple `Version`s, you can use the usual comparison operators to compare them:
+
+```rust
+use semver::Version;
+
+assert!(Version::parse("1.2.3-alpha")  != Version::parse("1.2.3-beta"));
+assert!(Version::parse("1.2.3-alpha2") >  Version::parse("1.2.0"));
+```
+
+## Requirements
+
+The `semver` crate also provides the ability to compare requirements, which are more complex
+comparisons.
+
+For example, creating a requirement that only matches versions greater than or
+equal to 1.0.0:
+
+```rust
+use semver::Version;
+use semver::VersionReq;
+
+let r = VersionReq::parse(">= 1.0.0").unwrap();
+let v = Version::parse("1.0.0").unwrap();
+
+assert!(r.to_string() == ">= 1.0.0".to_string());
+assert!(r.matches(&v))
+```
+
+It also allows parsing of `~x.y.z` and `^x.y.z` requirements as defined at
+https://www.npmjs.org/doc/misc/semver.html
+
+**Tilde requirements** specify a minimal version with some updates:
+
+```notrust
+~1.2.3 := >=1.2.3 <1.3.0
+~1.2   := >=1.2.0 <1.3.0
+~1     := >=1.0.0 <2.0.0
+```
+
+**Caret requirements** allow SemVer compatible updates to a specified version,
+`0.x` and `0.x+1` are not considered compatible, but `1.x` and `1.x+1` are.
+
+`0.0.x` is not considered compatible with any other version.
+Missing minor and patch versions are desugared to `0` but allow flexibility for that value.
+
+```notrust
+^1.2.3 := >=1.2.3 <2.0.0
+^0.2.3 := >=0.2.3 <0.3.0
+^0.0.3 := >=0.0.3 <0.0.4
+^0.0   := >=0.0.0 <0.1.0
+^0     := >=0.0.0 <1.0.0
+```