Bump version number and release 5.5.0 (#230)

* Update CHANGELOG.md

* Update CMakeLists.txt

Author: traversaro

CHANGELOG.md

@@ -5,6 +5,8 @@ The format of this document is based on [Keep a Changelog](https://keepachangelo
 
 ## [Unreleased]
 
+## [5.5.0] - 2022-02-01
+
 ### Added
 - New `RelativeJacobian` block that implements `KinDynComputations::getRelativeJacobian(.)` of `iDynTree` (https://github.com/robotology/wb-toolbox/issues/225).
 

CMakeLists.txt

@@ -3,7 +3,7 @@
 # GNU Lesser General Public License v2.1 or any later version.
 
 cmake_minimum_required(VERSION 3.5)
-project(WB-Toolbox LANGUAGES CXX VERSION 5.4.1)
+project(WB-Toolbox LANGUAGES CXX VERSION 5.5.0)
 
 if(WBT_BUILD_DOCS)
     add_subdirectory(doc)