Merge branch '615-opal-version-in-master-branch' into 'master'

Resolve "Opal version in master branch"

Closes #615

See merge request !450

CMakeLists.txt

 cmake_minimum_required (VERSION 3.1)
-project (OPAL VERSION 2.3.0)
+project (OPAL VERSION 2.5.0)
 set (PROJECT_BUGREPORT opal@lists.psi.ch)
 
 string (REGEX REPLACE "\\.([0-9])\\." ".0\\1." PACKAGE_VERSION ${PROJECT_VERSION})