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, 75 insertions, 0 deletions

diff --git a/rustc_version/README.md b/rustc_version/README.md
new file mode 100644
index 0000000..f491ca9
--- /dev/null
+++ b/rustc_version/README.md
@@ -0,0 +1,75 @@
+rustc-version-rs
+==============
+
+A library for querying the version of a `rustc` compiler.
+
+This can be used by build scripts or other tools dealing with Rust sources
+to make decisions based on the version of the compiler.
+
+[![Travis-CI Status](https://travis-ci.org/Kimundi/rustc-version-rs.png?branch=master)](https://travis-ci.org/Kimundi/rustc-version-rs)
+
+# Getting Started
+
+[rustc-version-rs is available on crates.io](https://crates.io/crates/rustc_version).
+It is recommended to look there for the newest released version, as well as links to the newest builds of the docs.
+
+At the point of the last update of this README, the latest published version could be used like this:
+
+Add the following dependency to your Cargo manifest...
+
+```toml
+[build-dependencies]
+rustc_version = "0.2"
+```
+
+...and see the [docs](http://kimundi.github.io/rustc-version-rs/rustc_version/index.html) for how to use it.
+
+# Example
+
+```rust
+// This could be a cargo build script
+
+extern crate rustc_version;
+use rustc_version::{version, version_meta, Channel, Version};
+
+fn main() {
+    // Assert we haven't travelled back in time
+    assert!(version().unwrap().major >= 1);
+
+    // Set cfg flags depending on release channel
+    match version_meta().unwrap().channel {
+        Channel::Stable => {
+            println!("cargo:rustc-cfg=RUSTC_IS_STABLE");
+        }
+        Channel::Beta => {
+            println!("cargo:rustc-cfg=RUSTC_IS_BETA");
+        }
+        Channel::Nightly => {
+            println!("cargo:rustc-cfg=RUSTC_IS_NIGHTLY");
+        }
+        Channel::Dev => {
+            println!("cargo:rustc-cfg=RUSTC_IS_DEV");
+        }
+    }
+
+    // Check for a minimum version
+    if version().unwrap() >= Version::parse("1.4.0").unwrap() {
+        println!("cargo:rustc-cfg=compiler_has_important_bugfix");
+    }
+}
+```
+
+## License
+
+Licensed under either of
+
+ * Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
+ * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
+
+at your option.
+
+### Contribution
+
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any
+additional terms or conditions.