Bump project version from 0.3.0 to 0.3.1 (#20)

To have a release compatibile with Eigen3 5.0.0 .

xref: robotology/robotology-superbuild#1902
xref: robotology/robotology-superbuild#1903
xref: conda-forge/eigen-feedstock#47

Author: traversaro

CMakeLists.txt

@@ -5,7 +5,7 @@
 cmake_minimum_required(VERSION 3.5...3.30)
 
 project(LieGroupControllers
-  VERSION 0.3.0)
+  VERSION 0.3.1)
 
 # ouptut paths
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_BINDIR}")