Bump version to 0.3.1

This change bumps the version of the crate to 0.3.1. The following
notable changes have been made since 0.3.0:
- Added note about interaction with GnuPG to README file
- Bumped nitrokey dependency to 0.4.0
  - Bumped nitrokey-sys dependency to 3.5.0
  - Added lazy_static dependency in version 1.4.0
  - Added cfg-if dependency in version 0.1.10
  - Added getrandom dependency in version 0.1.13

Author: d-e-s-o

nitrocli/CHANGELOG.md

@@ -1,5 +1,5 @@
-Unreleased
-----------
+0.3.1
+-----
 - Added note about interaction with GnuPG to `README` file
 - Bumped `nitrokey` dependency to `0.4.0`
   - Bumped `nitrokey-sys` dependency to `3.5.0`

nitrocli/Cargo.lock

@@ -19,7 +19,7 @@
 
 [package]
 name = "nitrocli"
-version = "0.3.0"
+version = "0.3.1"
 edition = "2018"
 authors = ["Daniel Mueller <[email protected]>"]
 license = "GPL-3.0-or-later"