Bump version to 0.2.3

This change bumps the version of the crate to 0.2.3. The following
notable changes have been made since 0.2.2:
- Added the storage hidden subcommand for working with hidden volumes
- Store cached PINs on a per-device basis to better support multi-device
  scenarios
- Further decreased binary size by using system allocator
- Bumped nitrokey dependency to 0.3.4
  - Bumped rand dependency to 0.6.4
  - Removed rustc_version, semver, and semver-parser dependencies
- Bumped nitrokey-sys dependency to 3.4.3
- Bumped libc dependency to 0.2.47

Author: d-e-s-o

nitrocli/CHANGELOG.md

@@ -1,5 +1,5 @@
-Unreleased
-----------
+0.2.3
+-----
 - Added the `storage hidden` subcommand for working with hidden volumes
 - Store cached PINs on a per-device basis to better support multi-device
   scenarios

nitrocli/Cargo.lock

@@ -19,7 +19,7 @@
 
 [package]
 name = "nitrocli"
-version = "0.2.2"
+version = "0.2.3"
 edition = "2018"
 authors = ["Daniel Mueller <deso@posteo.net>"]
 license = "GPL-3.0-or-later"